I believe, RIPE charges both types of parties the same amount for independent number resources and ASNs. Can't tell for the other RIRs. The main difference is that organisations are usually obtain LIR status as well in order to remove an intermediary between them and the RIR. And LIR fees are substantial (1K EUR sign-up, 1.8K EUR per annum) and individuals are probably not eligible for the status.
I think RIPE allows an individual to be an LIR because sole proprietorships are very common in some European countries. But you really shouldn't be an LIR for no reason, and the fee rightfully discourages that. If you want a PI block, get a PI block, instead of trying to pretend you're an LIR and then getting annoyed LIRs have high fees.
By the way it's high because the operating costs of the RIR are divided amongst LIRs - there's no other significant income source.