Buying parts has become a bit of a black art. Ebay is a potpourri, most of the "stores" sell junk, but you can find individuals on occasion with suitable parts for sale. Amazon generraly does not tell you where the stuff is sourced from, discounts, factory seconds or what. I like to get parts from Honda, sometimes they're reasonable, sometimes not. Rockauto, NAPA, those type places are sometimes useful. It really depends on the part, what you're comfortable with. Even China makes some good parts, the really cheap stuff is made elsewhere, now that they have a skilled middle class workforce. If you think that $100 starter from Amazon is the same as the $300 starter from a parts vendor, you're kidding yourself. Many stories of lifetime warranty parts turn out to be a lifetime of replacing and returning.