Here in the SF Bay Area you can buy yourself a ride in an L-39, which is about as "cheap" as you can go when playing in military hardware. The same aircraft is used for training for L-39 LOAs and airshows as well. Not sure if the economics would work out for pure joyrides. You'd have to find an awful lot of people prepared to part with an awful lot of money. I'd imagine you'd also have to work very hard to get all the paperwork squared away. They're all experimental and I'm sure insurance would be "exciting" to say the least.
Having said all that, if you can pull it off then good luck to you.