Well, it looks like I got lucky. My accountant says that I can keep using the one I have. I'll just quit making OS upgrades on this Mac, as I'm about due to get a new one, anyway. I'm retiring in a few more years. So, hopefully, I'm going to make it without ever having to buy from them again.

Meanwhile, I am kind of playing around with GnuCash. If, somehow, I need something beyond my planned retirement, I'll switch to that.

I hope Quickbooks gets what they deserve, which is to be consigned to the dustbin of history.