We did have a seller, who I'm sure some people remember, who went from an under 50 rating to over 100 in a couple of weeks. That was the guy that some folks claimed was basically blackmailing people for good feedback.
Kind of funny, I've been on for over two years, and I'm just pushing 25!
One seller says "over 25 rating, no negatives, I ship immediatly" otherwise he waits until the check clears.
Personally I've never had a problem with buying or selling on eBay. Like anything else, 98% of the people are honest, there's always that fringe that wants to twist the system.

I am getting tired of typing my name and url in, every day. What's up Doc? Chances are, it's my computer... <G>