The reason he has to cough up the money is: he has to post bond before he's allowed to appeal. So either he pays what he owes, or he puts up the money to ensure he pays after the appeal is overturned.
Ms. Carroll, unfortunately, won't see that money for probably another year, but at least she can rest assured that Trump is going to lose that appeal. Even if he becomes Supreme Dictator in November, that money is gone.
There were billionaires who donated as much Trump 2020 PACs so it's not completely unreasonable. However those billionaires likely did so control political messaging, it's not clear what they could gain here but I am not a billionaire.
I highly doubt the money will come out of Trumps personal funds, he has been fundraising for years and will likely continue to use those funds to pay for things.
He's received plenty of warnings but no repercussions. So he will continue stealing from charities and misusing campaign funds until there is an actual consequence.
ElMu pissed away $44 BILLION on Twitter to take over and destroy a public information spreading platform, do you really think that someone on his level wouldn't toss away $88 million to own the potential US president?