Currently auctions are done by placing a bid, and being outbid, and having to travel back to bid again.
What if, instead, bidding was done the way it’s fine in eBay. You indicate the maximum you’re willing to bid (and put up that much isk). You only actually bid enough to outbid the next highest person in the current increments.
This way you’ve indicated the most you’d be willing to pay, without having to commit all of it for sure if no one else is actually interested.