I don't really understand the problem? If it's cheaper on half.com , then shop there. The few times I've looked at half, the items have been of inferior quality. Of course Ebay does not have the bargains it used to -everyone knows about it now! Everyone wants that bargain, and on an auction site when lots of people want it.....
And yes, some people are really stupid. And yes it's irritating when really stupid people with too much money screw up your bargains. But that's life. Ebay isn't dead, it's just a little more QVC/HSN than it used to be. So are Flea markets. They evolved (so to speak). (Maybe backwards). Something else will evolve for the real bargain hunters.
As for the sellers with low prices and ridiculous s&h charges? I like them. They keep the eejits busy while I snap up my real bargain
