500%?

That guy is either stupid or you missunderstood something, because commission is the what you wagered edge, and I offer 50% of that. I don't think somebody will give you more than you made for him...
Sorry but you already in -0.183 negative profit, I don't know how would you pay does guys, for me it smells like scam, but let me wrong.
It's not a scam at all. You can't "smell" scam, I guarantee a payout, even if you wager 100 BTC.