The trouble with auction sites is that there are two types of products.
One is high-volume commodities, and for that you're just going to end up with a store. Even if you have a small seller, if a thousand people buy USB cables an hour, you're not going to sell it for more than what competitors are charging and you're not going to have to sell it for less. You ask for the market price and you get it right away. Efficient, boring.
The other is low-volume commodities. The issue there is if you list something for $250 and wait six or eight months, someone pays that. But if you put it up for a seven day auction starting at $250, it doesn't sell. And if you put it up for a seven day auction starting at $1, you get $25.
Which makes that the interesting one, because on the one hand it gives people an opportunity to get rid of their junk right away and make $25 instead of having to pay someone to haul it off, and on the other hand the buyer gets a great deal on something that would otherwise cost $250.
The problem is that it tends to make the sellers grumpy. A novice lists an auction starting at $1 expecting that in a global marketplace they'll get the market price, not realizing that the market price on a time-limited sale of a low-volume product is a lot lower than what you can get by demanding a higher price and waiting longer for someone to pay it. So they get $25 on something they expected to be worth $250 and they're dissatisfied with the auction site, or do something troublesome like refuse to send the item.
Meanwhile the professional sellers have been listing that product in their stores for $250 for months, but since there is only demand at $250 for one such item every six months and the novice just satisfied it for $25, now they have to wait another six months to get it out of their warehouse at that price. Assuming another small seller doesn't list another one before then.
And the auction site wants the sales to go through at the higher price too, because they'd much rather get a commission on $250 than $25. So they shoo away the troublesome small sellers causing all these problems.
Except that occasionally getting a $250 item for $25 was the reason buyers bothered to come to their site.