An idea that may solve the issue of players racing to be the final bidder, could be to incrementally and dramatically increase the minimum bid with each new bid.
How much the minimum bid should be raised with each new bid is something that may require a little thought. Increasing it based upon a percentage of the total bid, 10% goes to 15% goes to 20% more etc. may be the least complicated.
An opinion on the shady auction is that we use words to communicate ideas, shady can imply trees and sunlight, or it may refer to informal dubious dealings.