I would like to see a "Maximum Bid" option introduced for buying on a player.
It would allow you to pre-set your limit (e.g. 10 tokens & $2M) so that you can still participate in an auction, even if you can't be present (no internet, asleep, bidding on another player etc.)
It could operate much like eBay, in that you would only use up the tokens/dollars required to beat the next best bidder, not automatically go straight to your maximum bid.
If you logged in for the auction, you would automatically override your preset limit.