Not actually inowledgable about criminal economics, but... An offer from Group A to be protected from 'fuss' would first of all be based upon protection from Group A. If they offer more than that then it'll start with random street-crime ("we'll let you thugs do your thing, everyone's young once, but
not against [certain people and businesses] or we start by introducing your kneecaps to kinetic energy in soms form"), and may not go up to turf-conflicts with rivals like Group B (because that's already a Group-level conflict, and an externality to any particular racket/vendor 'agreement').
Group B being open to protect from Group A (and the 'allowable background crime'
and surely from Group B[1]) ought not to cost less than Group A, except as a loss-leader (or more marginal gain) as part of a larger manouvre to oust rivals A (where refusal to switch to B, when asked, could be
more costly than it was just being skimmed by A) that really doesn't give the 'protectee' much of a choice. Worst case: between the devil and the deep blue sea (perhaps in concrete diving boots, no helmet).
There's other deals to switch to that
might be cheaper. If you know an actual honest (and effective) cop, then maybe you can clue the authorities in on the whole thing (safely, hopefully at arms'-length from any traceback) and dismantle the threat for you and everyone else. (Though watch out for that criminal power-vacuum being filled again, as well as 'reverse informers' leaking your involvement in the process, however minor.)
Knowing a guy (whether or not you know you know) who happens to be be a vigilante with a whole-body-suit/golfbag-of-hockeysticks/
parasitesymbiote may be the cheapest option. You may get a bit of wear and tear on the premises when they happen upon "their favourite convenience-store/deli/barber/neighbour being terrorised" and decide to do something about it, but if they're that effective then they're gonna be (or start) cleaning up the
whole 'hood (maybe just the street, could even be citywide if they feel they can) and there's unlikely to be any more comeback on you than anywhere else. If your saviour lets it be known that they're going to stop criminals,
particularly anyone who tries anything on at the 7-11-cut-n-shave-gym-church-and-orphange that you run, you really have to trust that they (whoever 'they' are) have the ability to cow the local villains (and any external threats that might seak them out), but there's nothing you can do about it. Or do to get 'protected' in this way (save just being nice to all the quiet local kids, be willing to deliver pizzas to random manhole covers on request and always make sure that the back door is always open to the guy you've known since he was a kid who went away to serve ('time', and/or overseas) and came back with an understated but confident community-minded attitude).
But, really, if you've got a choice of 'Protection', then clearly no single 'Protection' is sufficient. (Technically
unrelated, really, but I've got that running through my head now. Scroll down to "Choices" subheader, or listen to it if you have access to it as the actual programme.) And this is something that maybe we can only hope that an AI will not understand.
[1] Or else they aren't a Protection Racket, but... Security?