So, we have been playing Ars Magica 4th ed for a few months and we have a setup where our covenant is lacking silver as a driving storyline aspect. It has been great but then we all sat down and realize that with the amount of terram vis we had, we could literally just conjure gold to take care of all of our debts. We decided to not allow that on the idea of perhaps that would count against the making a "permanent magic item". In any case, we need a system for maintaining and upgrading our covenant. The base rules are alright, but they don't have enough flexibility (unless we are looking at it completely wrong).
We would like to see something for gaining silver, spending silver, how to find out how much magical books are actually worth, etc. I suppose in short maybe some kind of general treasure system?