Hey guys, I'm considering getting a Macbook Pro retina 15 inch preferably with 512 GB and a 2.5 GHz processor. However, if possible, I'd like to get one used to save money. Where would be the best option to get one? Would it be Amazon? I'm very reluctant to use eBay just because I've never liked dealing with big purchases on there. Any other not-well-known places any of you guys know of to purchase a used or refurbished, fairly priced Macbook pro -- without having to deal with a headache of receiving a not-great laptop? Thanks.