If you are in or passing through MEM the Apple store in Germantown will definetly give you a FDX discount. Don't know how you would do it online. You can also get an education discount for any student or teacher in the family.
Another realllllllly good deal is buying a refurbished mac product from the web site. (store.apple.com or just apple.com then click on the store tab) From that screen go down the right hand column to good deals and click on that to see what they have to offer. I just checked and they have computers for $400 off list. Way better than any discount, and yes I bought one a few years ago. Came out of the box and could not tell it was not a brand spankin (gotta be careful using that word on this forum) new machine. Works like a champ and never had a problem.