Yeah, Best Buy's support service sucks.
My mom bought a netbook at Best Buy, it turned out it had something wrong with it. Think it was the memory, not sure. After about half a year, she decided to get it fixed. She explained the problem to them, suggested what to do, and they alway told her, "If that was the problem, it would never have worked." And they never listened when she told them that it never
did work.
So, they replaced everything but kept the same memory. She took it back later, clearly said that they tried replacing everything but the memory, and it still didn't work, so they probably shouldn't do that. Same thing happened.
Finally, the third time, she told them exactly what to do. She said to just replace the memory, nothing else. Despite the stores claims of, "Oh, it wouldn't have worked if that was the case," they finally agreed to try it. Guess what happened? IT WORKED.
@above
Actually, they aren't selling the update. They're selling the service of installing the update by turning on the PS3 and connecting it to the internet.
[Edit]
The one thing Best Buy ever did right was its old warranty plan, where no matter what, you get something worth what you paid for. As in, you buy an Xbox with a three year warranty, price goes down, you bring it in (broken) and you get a newer, better Xbox. But they got rid of that...
Also, quite some time ago (probably shortly before or after the release of Halo 3) they checked my broken Xbox with an expired warranty for red rings of death. Out of pure luck, it just so happened that when they turned it on, it got the red rings of death
Overall, everything Best Buy's support service touches has a chance of breaking.