I always try to buy B&M for anything that doesn't have a really high mark up. For most of their hardware, it is already somewhat costly to stock it, so the mark up is usually around 20-30% (in this area) where as online it seems about half that. Basically we are talking a difference of a few bucks to buy B&M vs online. Not to mention that instant gratification of picking it up at the shop and having it in your hand as soon as you pay!
I spent maybe $10 more for my iStick than i could have got it online for, but to replace it after buying online would have either taken a week or two for replacement, or another $35ish to buy a new one. B&M is the way to go. only thing I don't buy there is wire and cotton, the markup on that is massive.