If you go with Best Buy you can get Reward Zones points to help pay for extra accessories down the road. If it weren't for the EDU discount, I probably would have chosen Best Buy when I purchased mine.
Last week only i bought iMAC27 i5 from BB, i checked everywhere, even on MACMAll . MM has the same price as BB, not a penny less.
The best thing about BB is you get imac, right on the spot. no waiting for 2-3 days.
Yes, you will need to pay tax which was for imac ( $1607 ) aroudn $130.
But, if you have BB credit card, then they have special Financing for iMacs. ( 36 Monts, 0% , NOTE here, NOT 18 months, its 36 months...GR8 deal )
And you get $30 in Rewards...) and you have 14 days to return , no restocking Fees...
Thats the another story, that i return it after a week, just bcoz there are rumors that there might be new imacs ..nay be in next couple of months...and if not new, atlest refreshed config...
All the best.