I want to buy a notebook MacBookPro 13" used(second hand). The model that i want to buy is a 13" non-retina(late 2011 ) with i5 2,4 8gb120 SSD. What are the major objectives that i need to check before i should buy: Is there any way to verify the autenticyty of the product on-line. I guess i need to check the Baterry, HDD, the response time, heating time, and so on. Is there any betchmark to run to chech performances? MacBookUser please advice me. Thanks a lot.