I think it's a pretty cool idea but I'd really be really concerned as an end user that you're not just going to take my $50 and walk.<p>I'm sure you don't have that intention at all but you're basically asking people to hand over $50 to a dude in a street and then come back 1-6 months later to collect it.<p>You should incorporate some type of escrow service and explain to people that their money is safe there.<p>Also I'd be curious to see how many people don't just lie to get their money back.