Does a table which indicate the change values for the vis pawns to another form or tech vis pawn exists. And if positive ansewer, does somebody know where i can find it?
The general opinion is that vis values should change based upon local need and supply.
HoH True Lineages will tell you that, as a rule, the Mercere will in general exchange one pawn of any technique for 2 pawns of any form and then charge you an additional pawn of technique vis or 2 pawns of form vis for the service of doing the exchange.
I see this service as a sort of last resort for magi who can't make friends with other covenants.
Yes, Houses of Hermes - True Lineages, the section on House Mecere.
Form vis is abbreviated vf, and Technique vis as vt
1 vt is worth 2 vf, and visa versa
for exchanging, Hose Mercere has a standard exchange rate of 2 for 1.
2 vf is worth 1 other vf in exchange for another Art
4 vf is worth 1 vt in exchange for another Art
1 vt is worth 1 vf in exchange for another Art
2 vt is worth 1 vt in exchange for another Art
Privately, many magi may have much more reasonable exchange rates, based upon what they need. For example, I have a ton of Corpus vis, but I need vim to open items for enchantment. You have lots of Vim from extracting. We might work out a straight 1:1 exchange privately
I thought more about a table with different values.
Example:
- 4 Vim = 5 Creo
- 1 Vim = 5 Terram
with Vim as gold-etalon. I saw that my storyguide had a sheet like that...
I think that such sheets are apropriate but they'll change with location abd time.
My opinion is that rego and creo are perhaps more valuable than vim
Creo can make permanent items, can permanently heal and is used in longevity rituals
Rego is used in Aegis of the hearth and waiting spells (instant magic items).
Both are techniques and therefore have more possible applications than the form vim.
While vim is necessary for Aegis of the hearth and the opening of invested devices its value is limited by the fact that any magus can create it and thus the value can never be too great.
Err... Mark, it is the other way around 2 Form = 1 technique in value. At least as far as I recall 
Creo is more valuable than herbam, at least in my saga
Typo. I fixed it 
As Vim Vis can be relatively freely extracted and with Form Vis usually being more common as well as more useful, we have used a base something like this for "open trading":
1 pawn of a technique may be traded for 2 pawn of any form
1 pawn of a technique may be traded for 5 pawn of vim vis
2 pawns of technique vis may be traded for 1 pawn of any technique
2 pawns of form vis may be traded for 1 pawn of any form
3 pawns of vim vis may be traded for 1 pawn of any form
4 pawns of form vis may be traded for 1 pawn of any technique
10 pawns of vim vis may be traded for 1 pawn of any technique
If you go about and set up a direct deal, you can of course get 1-1 for equal value Vis(tech for tech, form for form, with Vim being the only "cheap" one).