When I bought my MBP (mid-2012 15" non-retina), it came with 4GB of memory so I bought at the same time 8GB of Corsair brand memory from Amazon. I installed it right away and began using the computer. It worked well for a while but then the computer started having all sorts of issues including random crashing--so eventually I decided to put back the old 4GB of memory that came with the computer and it seemed to fix it. But I want to have 8GB of memory, and Apple charges a **** of a lot for such a simple job. Is there anywhere I can buy some genuine, real Apple memory (i.e., the ones they would install if I paid them to upgrade it) so I can then just upgrade it myself?