When I used to resell laptops I bought from Goodwill (can't do that anymore - they now only sell fully refurbished laptops on their website, all stores send the laptops to a central distribution center) I would use eBay for the HDDs and PSUs because Amazon was ridiculous in price for the HDDs and the PSUs were always counterfeit and frankly dangerous since they overheated until the capacitors exploded. Buying online is ridiculous with shipping and the inevitable returns that YOU have to pay to do!