I keep my main with around 200 mill in loose change, any over that gets dumped in the FC bank for future reference.
Since buying the FC the balance in its bank has only grown greater, even with 30+ million upkeep some weeks...
All I'm doing is playing how I wish, not feeling I must 'earn' to pay for the upkeep...
Same here, except my ship carriers about 100MCr the rest is in my carrier. I have done very little mining since I got the carrier but I’m back at 3BCr in the carrier from Other Cmdrs mining. I go and do CGs and a little of everything else.