I wouldn't be the guinea pig on an unproven product that essentially holds up the entire weight of a car. Plus there is only a 30 day warranty on the product according to the ebay auction. Not worth it I would say.
I had to be patient, but got a great deal on TRD springs on Craigslist. I used this search engine to do a nationwide search.
Here are a few results when searching for Scion xB springs: 2007 - 2013 Scion xB TRD Lowering Springs (this guy is crazy asking $200 though for TRD's - you can buy them new for that!)
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