I think it's a poor sales tactic for some people, but I'm all for consumers educating themselves. But I do understand, I hate being sold a bundle when I'm simply trying to buy a single item, and that's the reason I educate myself, or buy everything online these days.
One thing I've found from as my 20's come to a close is that there are simply put, a lot of people out there, and a lot of them have a lot of money. It's hard to see this from the perspective of a guy making $12/hr from a mall kiosk (and trust me, been there), but people out there wandering the mall itching to buy $600 are generally loaded. They go to the mall knowing full well that they are paying a premium on everything they buy there. They don't care, or don't let it bother them, because they can afford to do that without thinking twice about it. Trying to sell people whatever they'll buy is part of your job and you shouldn't feel guilty about it. Of course part of your job is to size your customer up, and if all this added nonsense you're pushing is going to hurt the sale, you're right to not push it as hard.