The "problem" with Ebay is that it is an open auction.
The "problem" with any open auction is that amateur bidders (those who don't have a firm idea of their max and get carried away) see all the open bids and keep upping their bid to exceed them. They sit there in front of their PC, watching the other bidders, and get all nervous. You can see this plainly if you look at the bidding.
This is good for sellers, who get a lot more than they would get in a sealed-bid auction. I have sold stuff on Ebay (not junk; I never sell junk on there) for amazing amounts. Lots of people but and sell all the time and even make a small margin. If you buy e.g. a camera for £500 you can sell it (clean condition) on Ebay 2 years later for £250; this would have been totally and utterly impossible before Ebay came along (£80 in a secondhand camera shop, maybe).
It's also very good for Ebay.
But it's not good for buyers who have to outbid all the amateurs.
If you bid on Ebay with say £500, then Ebay will conceal the £500 figure and will present your bid as (roughly) X+£1 where X is the highest other bid. So if somebody bid £10, your £500 bid will show up as £11. Every time somebody ups X, Ebay resubmits your bid at a quid more - up to your £500 limit of course (but your £500 figure remains invisible, until the figure itself has been reached). This is a clever mechanism but it produces frenzied bidding among the amateurs who are bidding manually because every time they increment their bid they see you (what they think is you but it's actually Ebay's computer) incrementing yours.
If you know how much you want to pay, you are much more likely to get the item if you snipe than if you open-bid.