Ebay is in denial about this being an issue, and they believe that their automatic bidding feature solves the problem. Clearly they are wrong, as indicated by the proliferation of services like this, and the fact that people like me have been frustrated by having been sniped on numerous occasions. What I believe is true is that Ebay is really catering to the seller, who is paying the bills after all.
One advantage to sniping is that it lets you set your price in advance, then go away and forget about it and not get caught up in a bidding frenzy.
Also note that as of 7/2013 you have only 45 days to dispute a paypal transaction. This is fine in most cases, but I found myself in trouble with one situation where a fellow was making a custom item for me, made many delays, and then I found myself wanting to dispute charges after 45 days had gone buy. I was too much of a nice guy --- don't be!
I discourage buying from "liquidators". I have simply had too many bad experiences. The game definitely seems to be to sell defective items and hope that you either will not carefully test them or no want to bother to return them. A description will describe a minor dent and you will receive a useless item. An item will be described as "removed from working system" and you receive a broken device that turns lights on when plugged in. I have had enough of this kind of thing.
Note also that I urge caution about buying from overseas sellers. The main thing is to think about it hard. I buy a lot of small things that ship direct out of China and have had no problems. I have even purchased a fairly expensive item direct from China, and although I sweated quite a bit, it worked out just fine.
Here is an example of a purchase that went kinda bad.
Adventures in Computing / email@example.com