Probably couldn't as it would be ineligible for the coupon program.
My point was that they could have sold all TR-40's so that everyone would have been eligible to use the coupon on it and then the external hard drive could have been added for an additional cost. Basically that would have prevented someone that wanted the DVR version from having to pay the basic $39 cost plus the difference in price. I suppose they could offer a trade in promotion as well so that people could upgrade their free hardware for a more expensive one for an additional cost.