I would be very careful buying generic drugs in Mexico.
Lipitor is coming down in price as patents mentioned. And according to Kmowlegeable doctors, will have fewer side problems, and less hostile to the body.
Costco has been the lowest price for me, as I use a prescription discount card, at prescription counter in the states.
ASK FOR THE PRESC. MANAGER , as some won't bother searching it out. Makes 15% difference.
Also try Sam's club.