Does anyone what a power supply replacement on a 5,1 Mac Pro would cost at the Apple Store? I'm having the intermittent unable-to-power-up thing happening. Powers up on third or fourth click. Talked to Apple Support on the phone but they of course woudln't give me a quote or even a rough estimate over the phone. Trying to figure out of it's worth lugging this thing in to the Apple Store or just replacement it myself. The replacement part is $250-$300 new and about $130 for used pulls on eBay.