As we are only users here, this is something that you will need to take up directly with Adobe.
My local Best Buy had PRE8 in combo with PE8 for $75 in last Sunday's circular. I think you had to submit the rebate for that price, though I'm not certain.
Adobe does indeed offer and upgrade price to registered users of previous versions. All you have to do is ask!
However, between rebates and some of the deals being offered these past few weeks on Amazon and NewEgg, you can actually get it cheaper buying it from one of these retailers.