On freebitco.in when you place a bet, the expected payout is show under the box you enter the bet into.

Similarly, when a wager is won, there is a dialogue box showing how much your winnings are.

I'm away this weekend until Wednesday so I'll have to sort out the other screen shots when I get home.

P.S. to the OP, posts in games and rounds section aren't counted in some signature campaigns, so you may not draw as many competitors.