I don't think what you are doing qualifies as a penny auction. You are just
auctioning them away, fine.
There is a business model called penny auctions, where ebay-clone-sites
sell electronics for a very cheap price against highest bid, e.g. an iPhone for
20 bucks. The bids always increase by just one penny, hence the name.
But for the buyer this doesn't get cheap at all. You have to buy a package of
bids, and each time you place a bid you pay like 50 pennies. These penny
auction sites are next to scam. They are legal, but the concept is clearly fishy..
just smart-assing