Put up your offers on
https://bitoption.org/ - there you can NOT wiggle yourself out (PGP nice and fair, but as long as I don't have a lot of RL data I can't sue you anyways).
I like this idea, but how can I set what rate i want to payout for each btc invested? I dont see how this can help besides giving someone the option to trade the option.
Just read the help function or ask in the forum for details.
There are some explanations here, for example:
https://forum.bitcoin.org/index.php?topic=9611.120I strongly warn ANYONE of making deals just based on some PGP certificate (like on OTC). Bitoptions are backed by bitcoins/USD on MtGox, so they are far more secure for this kind of deal.