Office depot sucks. They kept pushing me to buy a 60 dollar cartridge of toner I didn't need, insisting that the starter cartridge in the printer I was buying "only prints 100 or so pages and then you'll need another one" which was BS, I've printed WELL over 100 pages and guess what? toner still works great and it hasn't told me it's low yet. they're just money hungry.
As for best buy, doesn't surprise me one bit. These are the same people that say Norton antivirus is the best product out there (no lie, they tried to sell it to me when I bought my vista upgrade from there). They also rip people off with their worthless geek squad crap.
I buy my compressed air at walmart or somewhere else. I find it's cheaper at other places, last time I checked it was like 6 bucks a can at best buy which is ridiculous. I usually buy it in the pack of like 4 or 6 since it lasts me longer. Asking for ID on compressed air is stupid, it's just air. yeah it can harm you but only if you inhale it or do stupid stuff with it. I've been using it since I first started computing, I've never had an accident.
Oh yeah, this reminds me I gotta go get some of that stuff. I haven't had any since we moved 3 months ago and my PC is very dusty. I know I won't be going to best buy or office depot