[patteeu]

I think you'd be better off avoiding anything that's actually random. I wouldn't be opposed to some algorithm that speeds up the process though, like the "buy now" for X% over the current price idea.

Or have the remaining bid time be dependent on how much the last bid exceeded the previous bid (or on how high the last bid was, without regard to what the previous bid was).

Or have the "buy now" price be set based on a current bid but then drop as the "time remaining" clock counts down.

I'm afraid that if it's random, people who end up getting poor random draws will get pissed off. If it's an understandable algorithm, they'll at least understand why they lost out on someone.