I've bought from MacMall twice. Their "NO RETURNS" policy sucks, but they process rebates in 4 weeks which is stellar.
I 'saved' over 400 dollars on my first iMac, a combination of rebates on the iMac (150 off), Parallels Desktop (60 back from MM), and a Printer (75 back from HP) made it a stellar deal. No Tax just sealed that deal.
There was also a P.D rebate for 20 from the MFG, which made P.D free.
So Essentially I got my iMac for 150 less than Apple sells it for pre-tax, P.D 3.0 for FREE and a printer for FREE. I think they may have had a slight discount on the product pre-rebate so I may have even gotten it for less, I cannot recall at the moment.
I've done this twice now and when it comes time to get a notebook I'll surely look at MacMall. No tax also helps too.
Oh, Also if you purchase through Fatwallet's link to MacMall you get 2% back from FatWallet after 120 days, which amounts to another $40 bucks on a 2000 dollar purchase.