Why are these pistons so cheap on this site?

RustyDusty said

They're 60+ at Advance Auto as well. Half off just seems too good to be true! http://shop.advanceautoparts.com/we...n-sealed-power_15680050-p?searchTerm=h116cp30

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Advance and the other chain stores jack their prices sky high for regular customers, if you've got a commercial gold account they'll knock it down by nearly half sometimes.