Yes, I am stingy and I love a bargain, I also have this embarrassing habit of sometimes haggling even when I have been offered a good price (I do feel shame). I guess I have seen too many bargains come my way and I am spoilt. Yet when the item is exactly what I am looking for then I will happily pay a retail price for it.
Ebay auction prices should be lower, we can not handle the goods as already mentioned and in various extra ways problems can occur. However, there can be a fantastic variety of items to choose from, you can pick up bargains and I frequently enjoy buying and selling with what turn out to be nice people. With a bit of effort and experience (and a few questions to sellers) you are more likely to avoid the bad sellers and items. Have realistic expectations and bid accordingly, there are always more fish in the sea if you miss out on something.
As a 'hobby' seller on ebay I have only had one problem (touch wood), a buyer gave an incorrect postcode and the item was eventually returned to me. As a buyer my problem transactions (usually to do with condition) could generally have been avoided if I had been a little more careful.