You have to use the MSN Wallet thing. Goto Circuit city. They have this drive for $109.99 with $60 in rebates. You get $22 in MSN dollars. You can try PM-ing it with BestBuy which has it for $89.99. So you may get $20 in PM-ing.

Now calculate 109.99 - 20 (PM) - 22(MSN) - 60 = 7.99. May be you will lose $2.00 if your PM succeeds. So it will 9.99.

Risks:
CC should PM BB. BB also has it for 109.99 but they $20 instore savings which makes it 89.99

I was successful in PM-ing CC with BB's price. So i guess this would be hot. Also MSN Dollars can be converted in to actual money if you close the account. So this is SUPER DUPER HOT.