Is It Possible To Still Upgrade To OS X 10.8 Mountain Lion? For those Mac owners still on OS X Snow Leopard, does the possibility exist to upgrade to OSX 10.8 Mountain Lion rather than to 10.9 Mavericks?
Yes, Apple sells older OS as redeemable downloads from the web store.

Apple sells OS X Mountain Lion redemption codes, alongside OS X Lion, for £14 each on the UK store. 

The US store link is below and it appears the part number is the same no matter which store you select:


http://store.apple.com/us/product/D6377Z/A/os-x-mountain-lion
http://store.apple.com/us/product/D6106Z/A/os-x-lion