Um werid guys, is this in the new "cough" features of TA. In DA I am always running between 50k and 100k BC in my treasury about the time in get Disruptors
No, the 20k cap has been around since the beginning I believe. It's not a cap, per say, but your income is
greatly reduced if you have 20,000bc or more in your treasury. It is even possible to
lose money by having a treasury that high. It's mainly a problem because, late game, you start running out of things to buy each turn, especially once warships and wonders start costing over 20,000bc each...
Also, your trade income is reduced (halved, maybe?) if your treasury is 10,000bc or more. This one makes even less sense to me than the 20k limit... and don't get me started on the -500bc when you're making 10k bc a turn thing...
I think the real problem with these limits is they are hard amounts that don't scale with your economy as a whole. Your tax/trade income isn't gradually reduced as your treasury grows, instead, once it hits a certain amount, *BAM*, the full penalty kicks in. It's the same deal with the pop growth bonuses/penalties from Approval; it's an all-or-nothing deal.