clean sweep auctions and the penalty for bidding late

[sports-rings]

I have never participated in a cleansweep auction and there is an item I am interested in.

The auction ends tomorrow and in reading the rules it states that they discourage bidding in the middle of the night by increasing the buyer's premium as the auction goes late into the evening.

It looks to me like they don't use Simple auctions (as far as I can tell). From what I understand, auction houses do not know your maximum bid if they use Simple Auctions software.

I hate to reveal my budget to strangers at the auction house and all the talk over the years of auction house ethics, issues and conflicts of interest is not helping lessen my concerns.

Furthermore I reached out to them last week and they never returned my phone call.

Does anyone have experience with cleansweep and has anyone put their max bid in early and had positive results?