Are you looking for new or considering used with warranty? I ask since am selling my 2012 2.9/8/768 13" rMBP in Ebay, but have also considered passing it to my daughter and then selling her 2.5/8/256GB 13" rMBP (both machines have Applecare and are in excellent conditions). PM me if interested.
MacMall is an authorized reseller of Apple products. They were the cheapest option for me when I bought my MBP a few weeks ago and were quite pleasant to deal with.