At an auction, if nobody shows up that's a collector, especially if there's only a small amount of coins ($1,000 or less), it's juss not worth the time of a serious collector. So you may be bidding against all newbies juss looking to spend a few $$$ for the fun of it not knowing what they're bidding on or trying to get. That's when you get good deals.
It's so difficult to tell from these images but the 1799 and the Trade Dollar are fair obviously bad. I'm not pleased with the look of ANY the hunks of metal (I assume). But I'm no expert.