In my article on Buying BRIO on eBay I point out that eBay is not typically a bargain when it comes to items that are still sold in retail stores. A good example of this is the #33253 Stacking Track Supports, which I very frequently see for sale on eBay in the U.S. at inflated prices.
As of August, 2014, this is sold for less via Amazon, with free economy shipping:
Sometimes you can do even better at traditional brick-and-mortar establishments. In this case, Finnegan's Toys in Portland, OR:
Just because it's sold on eBay, that doesn't make it a deal.