Big box stores may as well have no tech support,never not once have any in store tech gurus been able to answer my questions on the spot unless they come up with some psyco babble,the bad part is that most consumers have very little understanding (if any) in these matters & not until they have a problem with their new system do they realize that the in store tech support is a bunch of slick talkers.
My local high end shop charges best buy, circut city & internet direct customers for set up help when the instore people cant help them , im told it plays a large role in the overall income of their installers.