The $2500 A
tocha Dive Adventure trip is run exclusively through SingleDivers.com, or at least it was. They take up to 6 folks out on the Magruder or the Dare and actually use the mailboxes and blow lots of sand everywhere so it can settle on the reef. You may keep up to $2500 of what you find, if it is worth more than $2500 you can buy the rest. HOWEVER - what you find must be conserved. You wouldn't want a $2500 emerald because it would be powder by the time you got it home, so you may not see your find for many years. It also has to be registered with the State, run through the process, etc.
These guys are genuine archeologists. Yes, Mel was a cowboy/pirate, but the boys and the folks in charge now do it in a much more archeologically satisfactory fashion.
The 10 grand buy in is for a share of the treasure as an "investor". It does get you an opportunity to dive as "crew", and when the proceeds are split at the end of the year, you get paid out in cash or treasure for your share. There are still lots of kids in Key West waiting for their turn as crew on the Mel Fischer boats. I know quite a few folks who have done the SingleDivers trip once.
You know how treasure hunting works, right? The treasure is in your wallet unless you give it to a treasure hunter. If you have the $2500 to blow on what is undoubtedly a unique vacation, go for it. If you expect any return besides memories, well, you're just who they are looking for.