I don't know about anyone else here but it sounds like a nominally legal, if morally dubious, startup idea. Each month put a 'treasure' somewhere, and sell a description for $10 on how to find it, once a year do a "big" treasure ($100 ticket) for people who have participated in 6 or more of the previous months.

The barrier to entry would be the ability to make reasonably challenging ciphers. The harder the cipher the more hard core the participant, but you need to sell enough "tickets" to cover the cost of the item and operating overhead.

Sort of a variation on puzzle rooms.