Do what I did. Care not a bit for what other players would think, and take what you think is essential to the covenant and/or your own character. Note the array of books, and specialists I took? Books are for my character, specialists are for the covenant.
Well, books are insanely expensive when using covenant build points to get them, and that's a fact. Particularly mundane book (which this summa isn't). It only makes sense to get that rare high level high quality Art summa that the ST wouldn't let you have otherwise without 3 years of roleplayed negotiation. But a covenant should have some books anyway from a roleplaying perspective 
How is this book not mundane? Code of Hermes is an Ability, a restricted ability only by dint of someone needs to know about the Order of Hermes and have some understanding of the legal constructs of the Order. A character could be built to have the same amount of knowledge, while possessing zero magical skills.
Code of Hermes is qualified as an Arcane Ability, and I was referring to the classification in Covenants, in particular the "Prices for Books" page, where books are divided between "Mundane Books" (books that can be found in Universities and stationers in large cities) and "Books Concerning the Arts and Arcane Abilities". I very much doubt books regarding the Code of Hermes can be had outside the Order ... not so much because of any secret or magic required, but because no one else would be that interested.
No, but books on Arcane abilities can be written by mundanes, with the relevant knowledge. It may not be widely available in the world at large, true. But a tome on this is probably quite a bit easier to get than a book on the Arts is, because they can give 30 tractatus compiled over several years to a mundane scholar and say hey, read these, and synthesize the information into a good tome. 8 or 9 years later, they get a good summa back that can be copied easily and disseminated to the Tribunal, and Tremere throughout the Order.
There, we found him ! He's coming out of a house in the street of candlers, opposite the burning apple ! Peripha's mental voice had a strange echoing quality, as if two people were speaking in together in perfect harmony, and that despite the fact that at the moment Peripha was supposed to be in the shape of an ordinary, one headed falcon.
Diotima put down the manuscript she was poring over and thought back. Burning apple ?
It's a red apple with the stem on fire, painted on the wall over the door !
Ah, the shop must specialize in scented candles then.
And now he's proud as a young stupid robbin who's just caught his first mate. You know, we could kill him right here and now. Simple and easy.
Too public, my friend, too public. Let's do it my way.
All right, but remember, you owe us an ox for finding the place. With the two oxes for flying to Constantinople, and the one from eavesdropping at the palace, and the three from eavesdropping in that really itchy place...
The Hagia Sophia ? why three ?
as we said, the really itchy place, and we hate changing into a stupid stone human with wings. So that's one for eavesdropping, and one for the itching, and one for taking the stupid shape. And the three oxes for following that young rooster all week, whoever he is...
He's the ambassador from Venice
Venice ? The place with the flying lion ? I wonder if it's good eating. I hate a winged cat once, but it was only a small one.
It's just a statue
Anyway, you owe us eleven oxes already, big fat one.
I'll have them for you when you come back. Now, I'm going to need you again tonight. I want you to find a nice big rock, and when I tell you I'll need you to turn real big and black, it will be night, and drop that rock on the boat I'll tell you.
All, right, but this time we'll want a horse. The biggest horse you can find.
Deal. Now, excuse me, I need to work.
Diotima rose and opened the secret drawer in her desk. She took out a small box, which contained two scrap of bloody cloth. After double-checking that no one was approaching her tower she barred to door to her sanctum and started a complicated double casting using two spells she never mentioned in public.
In Constantinople, a young ruffian suddenly decided to pay a certain house in the streets of candlers a visit, certain he would fine some nice jewelry there. He went in search of his usual partner, who readily agreed.
That same night, in Constantinople, the young mistress of the ambassador from Venice died in a robbery gone bad. A little later, a boat with two men on board, who almost certainly did not own it, started crossing over to the Asian side. Suddenly the men collapsed, one after the other, and the boat stopped in the middle of the narrow sea. Shortly afterwards a large shadow flew over, something fell, there was a loud crash, and the boat and its occupants sank under the water.
Somewhere in southern Italy, Diotima smiled and threw a box into the fire. She wiped the sweat from her brow. Thank you Periphas. Now, I'm going to need you to take human form, write a short message, and drop it in the garden of the ambassador from Nicea.
We want two oxes. One for changing into a human, one for dropping the message, came the immediate reply.
All right. Now, the message is: the ambassador to Venice will be in no mood to discuss the alliance offer from the Latin Usurper for a few days. He should also be receptive to a young lady's tactful advances, and might forget the matter entirely if you move quickly. Sign it Plytapus.
You'll owe us thirteen oxes and a horse.
And I'll need you to eavesdrop some more for a few days, then you can come home. Your herd of oxes will be waiting.
Big ones. Remember, eavesdropping is one ox per day
Of course.
Sighing, Diotima opened another drawer and withdrew a small chest. Only a handful of silver coins remained, not enough. She would have to sell some jewelry. Well, she still had plenty, far easier to store than silver. But the price of livestock near the covenant had become noticeably higher than when she first come in. It really would be ironic to be reprimanded for interference with mundanes for messing with the local beef economy, of all things ! And she had had too many close calls with peasants needing their memories adjusted after they saw a giant eagle playing catch with itself and a mooing bull. Better to make it a clean break. The Latin Empire's days were counted, anyhow. Time to write to Emeritus ex Tremere again, and slips some more hints about those Roman ruins at Keszthely.
[hr][/hr]
And now you know why Diotima really needed a wealth creating spell 
#3 I have covered for other characters. You are free to sell your magic items to any Civis or Socii. Otherwise a local Redcap will act as a broker. This is written into the Tribunal code and is not up for negotiation. No vis sales or magic item sales to anyone other than Civis or Socii.
Parts 5-7 are crossed out. As the Tribunal is paying for the study of the area with little to no investment from the magi, the Praeco will decide on distribution of any artifacts found.
What about translations ? They are neither vis nor magic item.
You are allow to sell your services. That part is fine. The magic item part was not.
Right, I rewrote that clause in the original post.
Regarding the clause 4 to 8 of Chapter III, well, you've certainly been very generous with the covenants' resources (far more than I expected when I wrote those), but Diotima is still investing her time, expertise, and possibly her mundane resources (depending on how many grogs she can borrow from the Covenant). What do you think she should get out of it ? I'm pretty sure that if she digs up a chest of gold coins, the law of the land makes her the owner, or just possibly the local noble (yeah, right, like I'm going to inform him), but certainly not the Tribunal. Ditto ancient texts. Vis on the other hand is probably claimed by the covenant under its charter...
It depends on what she is borrowing grogs to do. 
The charter gives you a broad hand in exploring the region. Now if you take the grogs to explore the Roman ruins of Trier you will be on your own for support as you are outside the charter. You could keep what you found but if you piss someone/something off the Tribunal will not help.
It is not like your grogs are going dig up an ancient scroll and the Praeco comes out from behind a tree to take it. Anything you find for the Oppidum, you can catalog/translate/experiment. A report is sent to the Tribunal on what was found and then the Praeco will send back what is to be done. It is most likely that any wealth will be kept in the Oppidum. Other things will be decided on a case-by-case business.