((Feel free to get Korvin. Just like he considers you his contact for the Church))
Alexei thinks for several moments. That vis wasn't often used so far, but perhaps they were planning on making use of it for the Tribunal and the buildings? "Let me...see if that vis has been spoken for. Can I return to you directly in a short while?"
((Assuming so he'll pop back to Mons Electi and find Korvin and let him know of the situation and also check the vis stocks.))
Vis stocks in 1223 would be slim, I think. The covenant typically dispersed stocks. I'm unclear on what happened with all the Intellego Vis Alexei acquires from the tournament.
If Alexei asks Korvin, he will come back with Alexei and bring a bottle of wine.
((Alexei was going to grab as much of his own Vis, some of the Intellego was used for his Talisman but that's maybe about 4 pawns. So he'd grab all the rest of that, and since it's Technique it should be worth more. I'm not sure where we are the on the rest of it. To be honest, I have no clue as to the dispensation of Vis. Alexei is a bit scatter brained on that due to his Personality traits, but that's no excuse for me.))
Alexei meets Korvin and tries to give him the rundown as fast as he can while gathering vis. "So she's asking for 45 pawns and it simply does not seem that it should be so very expensive, do you agree? I assume you have a connection. If you are ready, let us depart. And thank you again my friend."
For what you are asking it seems fair but I know Sevrin so perhaps we can bargain. Let me get the ledger and I'll meet you at the Portal.
After transport, Korvin heads to Sevrin's office and asks one of her assistants to see if she can see him on the matter of Alexei von Kroitsau of Mons Electi. Then he sits and waits. Chatting with the other overworked assistants on what is happening and the latest news and gossip. He will try to ignore Alexei's pacing about the room.
((He is not trying to get information. Just being nice.))
Korvin and Alexei don't wait long. Korvin's presence, while distasteful to some of the Redcaps, isn't distasteful to Sevrin, and she welcomes him quickly, dropping whatever she was doing to see him immediately.
Turning to Alexei, "I see you brought help." Turning to Korvin, "We're starting with 45, and thank you for the wine, but we're still starting at 45. There is the matter of transporting into possible danger, so that means we need to take some armed redcaps who either have their own means of transport or are willing to accept some warping, and transport back...more warping, or they have to travel back mundanely. 45 pawns is not an unreasonable amount. But hit me with your counteroffer, Korvin." She strokes his cheek, while taking the bottle of wine from his hands.
Korvin will gently hold her hand against his cheak then bring it down so he is holding it in both of his hands. He leans into so he can speak in her ear. You really must make use of the portal to Mons Electi.
He straightens and looks into her eyes. I know the offer is fair and I told Alexei this. While I will support my friend and Covenant-mate I must also support my House. We can give 30 pawns of vis today. 2 rooks of Herbam and 1 rook of Mentum. Korvin turns to Alexei. Alexei will have to pay some of it back to the Covenant but that is for later. For the other 15 we can bargain. Perhaps you can find some use for a season of Alexei's time or mine. You know my specialty. He kisses her hand. Alexei is a very skilled soldier and accomplished magus. Or, if you wish you can give us a year to pay the other 15.
"Korvin, you know I'm far too busy." She declines his offer gently, and perhaps a bit unwillingly.
"The Herbam vis could be very useful to us. I'm not sure if you noticed the construction going on...but we could use a spell that could construct additional warehouses. It would allow us to focus funds and labor into other more necessary areas. So if someone could make us a ritual to make our warehouses, even if they aren't ready right this moment, but sometime within the next year, it would be most helpful."
Creo Herbam ritual. Korvin looks to Sevrin to confirm and then back to Alexei. Might only be a 3rd or 4th magnitude spell. Are you up to this task my friend?
((It's probably more than 4th. And it's certainly no less than 4th magnitude.))
"That's a task for a magus, not me. We just need a copy of the lab text, too."
((it was not clear that I was talking to Alexei. I was looking at Base 3 Touch +1 Size +3 or +4, Perhaps simple design +1. This is based off of Wizard's tower.))
It's a ritual, they are always at least 20th level, even if they are less than that in the determination of magnitude.
Look at this spell for inspiration, and run the final spell designed through the troupe for some comments...
That spell creates various pieces of wood of differing sizes; this spell would need complexity to assemble all the pieces into a final form. I think T: Group and Base 2 are better than T:Ind Base 3 (which is like a huge hollowed out hunk of wood of gargantuan size. But either approach is possible. I just want someone else's eyeballs on the final spell designed/submitted.
Or...go hire a specialist. 
Looked to Sevrin to confirm it was herbam then look to Alexei
Creo Herbam rituals do not require the wood. Same as Creo Terram rituals do not require stone. You are looking at ReHe spells that require finesse to put the structure together. This is not building a complex structure but a simple one.
I'm not saying that CrHe ritual spells require the wood.
I'm saying that the ritual I vaguely suggested creates the wood (pieces) and puts it together in a finished form. Base 3 would create a giant block of hollowed out wood. Even within the paradigm, cabinetmakers will tell you this is a bad idea, as the wood will warp badly over time. I have to take some cupping out of my workbench, and it's not even a solid piece of wood. It happens. Trust me. 
Then make it with stone since any wooden structure would be crap in 5+ years.
No...no...no...
The ritual I'm suggesting, while based on the spell I outlined actually puts it all together, very much like Conjuration of the Seaworthy Cog (from Hermetic Projects) does. Maybe I should have referenced that spell...
That spell (CotSC) has problems as written, in HP, though. It's T:Structure, not T:Group, but changing it to T:Group and adjusting the size component will leave it the same level.
The Ritual will put all the pieces together, and while it is a simple design, you're assembling a lot of individual pieces, so some complexity is necessary.
Conjuring the Mystic Tower creates a piece of stone, with hollowed out portions for each floor, and a layout specified by the ritual, which makes it complex. No need to shape anything else anywhere.
Am I making sense, yet?
Only in the sense that making a wooden structure with magic is more of a pain in the @$$ than just making a stone structure. Even the examplethat Peregrine is more involved than just making it from stone. A stone version of the same spell would be CrTe25 rather and CrHe(te)30
IMHO, This would be ReTe in this case with a load of finesse to get it right.
((Wow, a bunch went on while I was getting lunch and comics. For the record Alexei has a decent Finesse with a specialty in making things with magic.))
Alexei mostly stays quiet during the rapid fire exchange between the two and was pleased that real progress was being made. At the mention of both the protection of the Redcaps and Harco grogs Alexei smiles. With the mention of the warehouse and its permutations he sees his opening.
"My Sodales, I appreciate the concern for the Redcaps and grogs, but truly, they should not be needed. Their danger would be from Warping of course, which would be avoided altogether if they don't go. They were left on a long abandoned stretch of road in the Holy Lands. As for the Ritual, Creo and Herbam are some of my more formidable Arts, and as for creating things..." he pauses and his eyes unfocus a bit and a smell of rich wine fills the room, and a suit of shimmering armour appears in his hands. "Creation and the skill that it comes with is something I am quite adept at."
Output: Finesse roll 6+ [1d10] = 10 as this was not Stress he just rolled a 16
unseenservant.com/Default.asp?do ... &what=sand
((I hope I did this right, I've made 2 rolls and both are 10))
Not really...
CrHe Conjuring the Mystic Warehouse
Base: 2, R:T, D:M, T:Group, Size +3 (on Group) makes 10,000 pieces of wood.
Add +1 for complexity to assemble it into a warehouse shape and it's a Level 25 spell. +2 complexity would be 30th level.
Conceptually, you're imagining a finished warehouse, what does it look like and what is it made of. It's made up of a butt-load of wooden pieces. Some metal pieces, but we can handwave that, or they could be joined together with dowels and wooden pins, and later fastened with nails...but anyway, I digress. Yes, you need a Int+Finesse roll, just like any Creo'd item to get it to look decent, but a EF of 6 is sufficient.
There, I designed the spell for you. 