Is there a practice penny auction site where all bids are free?

[Kevin]

I would first recommend staying away from these as you will not make your money back. I have used a handful of them and they are all the same.

Even if this existed it would not benefit you in anyway. If you are bidding against someone else who is using free bids as well what is their incentive to stop bidding? There is really no such thing as practicing. The only advantage you can gain is following the bid from the beginning and tallying the amount of bids each person has used. This can give you a general idea how much further they are willing to go (based on the amount they've already spent) if you start bidding head to head.