I think you should receive a percentage of tokens with each sale, otherwise you always lose money on players you sell due to the amount of tokens spent to obtain the player in the first place. Also I think if you lose an auction you should (after say 10 minutes) get half of what you spent back as you lost. Or maybe be able to see how many tokens your opponent has to see if its even worth battling with them.

I went to level 54 with someone and the price was 15 mill and with 12 seconds to go in round 55 the bid just ended and i was informed i lost the auction. Was not happy!