Player 17:
The actual bookkeeping is easy. I built a spreadsheet that handles it simply. I suspect that most people don't want to focus on stories related to how the covenant earns mundane cash. Or about recruiting craftsmen or other servants for the covenant.
The cost of labs keeps getting mentioned. Setting up a standard lab costs £5 over two seasons. Maintenace on a standard lab doesn't really cost much, but when you start getting labs with increased Upkeep, they get pricey.
I kinda dislike the covenant accounting rules for Ars magica. I think they're *fine*, but then the entire covenant book seems
based around them. The lab mod rules are cool but require Upkeep as a balancing factor. The real thing where the accounting rules become weird is when you allow them to change. There are a required number of servants per inhabitants, and there are no rules for what to do if you're below that number. "Two more magi moved in with a horse, the Cook has suddenly spawned three full grown children to compensate."
I usually see Companions and Grogs focused on mundane income for a covenant, actually in play. Though I admit my examples are limited (a few aborted online games, 3 IRL games). I think though, everyone is going to WANT to use the lab rules and the get those extra bonuses, because they make fun labs.