Just did my math again on this:
Currently I have $39.99 ($40) a month, one year subscription fee is roughly 12x39.99=$480(I omitted the tax just for the sake of easy comparison).
If I get on the CompUSA deal, it will be 12x29.99=$360+199.99(modem)+29.99(start kit)+11(sales tax)-175 (rebate)=$426.
So for one year, if nothing else happend, I save $54. If the modem is dead, I have to send it for warranty repair (if there is any), and have days or weeks without internet (still being charged by AT@T, though). After one year, I don't know if I will still be using cable internet.
I might pass this deal. I agree though, this is a good deal.