Mike has summed it very well.
You can't get ripped off on eBay unless you participate in ripping yourself off. No one forces you to up your bid.
When I bid, I set a maximum bid and walk away. Shills can do what they like. I do my research regarding market values in determining what my maximum bid will be. Depending on make, model, and condition, my maximum will range from 2/3 to 3/4 of new. Occasionally it's less if a maker's resale values are lower.
I also ask questions of the sellers, ask for more pictures if I'm not satisfied with what has been posted, etc.
You can use eBay's advanced search option to see what prices items have brought in previous auctions as part of your research. That will give you an idea of the eBay market price range for an item.
Despite the hype, eBay doesn't exist to offer steal deals. Occasionally they do happen. I've had a handful in the thousands of auctions in which I've bid over the years.
The occasional super high prices aren't necessarily the result of shills. A particularly rare and desirable item can spur duels to the death between determined collectors. But in the end, the price was what someone thought the item was worth to them.
