Well, my interest in this likely won't last since I've already gone below $100. Still a small amusement.
Eh, if you break bank it'll go up to a bailout limit. 20's the base, which raises as your level increases (which happens as you make bets). If you're looking to make money, really, the best option that doesn't involve spreadsheets or automation is simple flat memorization. After several hundred matches, if your memory's good enough, you'll start being able to make good predictions as to who will win 'cause you'll have seen both fighters at work before.
Of course, after over nine hundred matches bet on, and probably a few hundred more not, I
still haven't seen all of the roster, and there's still more than a handful of dudes (especially among the trickier fake ones) I can't recognize well enough to bet on well. So... yeah.
I dunno bout ya'll, but I like actually playing MUGEN, rather than watching the AI beat the crap out of itself. 
Eh, I'm terrible at fighting games, and half the fun of Salty is just the scenarios that occur. S'a lot of just... great stuff. Watching the Asteroids ship blow up Darth Vader is wonderful. Seeing Nanoha XP beat the everloving shit out of everything, etc., so forth, so on. It's better than TV.