Also, in many auctions there is no "end time". The auction continues until nobody is willing to beat the highest bid (aka "going once going twice SOLD!!!"). Perhaps another option would be to end the auction after X blocks have passed since the last highest bid?
This is a nice idea. For instance: Auction lasts as long there are blocks with higher bids than the previous high. This may also solve "bids to close to the wire to be included" problem. In your opinion, should the system show the bids from the current (Edit: unsolved) block or publish them after the block is found?
I would say only bids included in solved blocks to avoid shenanigans.