Why do you only want to make one bet? I think that's a huge risk to be taking on deice. You will probably win it, but you will be risking 105 BTC for 25BTC? That is nothing compared to the coins you already have, so those 25BTC should not be that important. Also why dice? Why not sports betting? You have a better chance of controlling your wins there. There no guaranteed wins, but there are a lot of good tispters that normally don't have problems winning at those odds, so you should get those 25BTC in no time.