sadly, this does happen. it might be shady, unethical, against company policy. without stating that the advertised price is based upon the purchase of additional items and services, it could quite possibly be illegal as well.
we had similar happen to us at BB one year. this was 3 or 4 years ago, so the exact details are a bit fuzzy. pretty much it was like this. we were like 3 to 8 in line, got vouchers for things. once inside, found out we had to wait in a massive line in the computer area to redeem them. everybody that was buying a computer had to go through a "consultation" where they had service plans, accessories, installations, security suites, seeing eye dogs, and fireworks safety classes pushed on them. hey, this is BF, nobody is there to spend "extra", so it was a giant time suck. we finally get there, and are told they had no more laptops, at least not at the doorbuster price. they said that a voucher only guaranteed that a laptop would be available, could be any brand, any model, any price. we were pissed. they then said that they did have the ones that were on sale, but they had already been "optimized" and had the security features enabled, and were now $200 more. we told them that this was BS, and fought to get them at the sale price. they tried to sell us on the upgrades at half price, but we didnt budge. finally, they relented. but they could not give them to us now, as they did not have time to uninstall all of it right then, and we would have to come back after 5pm that day. ok, fine. we came back later, well after 5. they couldnt seem to find them for us. finally, they said, oh, sorry. that several of them had bad hard drives and they had to send them back to the vendor. they would refund our money, but we would have to come back to do that on monday. we flipped out. with threats of returning everything we bought that day (over 6K), reporting them for fraud and false advertising, they somehow figured something out. all of a sudden, a guy comes from the back with some laptops. all factory sealed. interesting. they told us they had already done installs on them all, and also determined they all had faulty hard drives. we reported all this to a regional manager, as well as corporate. not sure what happened to those at the store responsible for it, but we did get some gift cards out of it.