We killed off music stores by tire-kicking in the store, then buying on line to save pennies.
There's a good point to be made here, but it's not exactly "pennies" we're talking about.
Personally, I try to frequent my local mom-n-pop music stores and buy everything I can from them, from instruments, to strings, effects pedals, and other accessories.
One store that I go to often, I purchased a bass that was over 3 grand a few months ago - I could have gotten it online for much less, but I want to see the store be successful and I like the people there.
However, a few weeks ago I stopped in and was checking out a new bass that caught my eye when suddenly I started getting the "hard-sell" treatment from a fairly new employee. Nothing makes me shut down on buying something like pushy sales people. Now I'm online looking at the same instrument in the same brand new condition for about two-thirds of the cost I would have paid at that store. Not saying I'm gonna buy it online now instead of the store, but it sure makes me think twice.
A lot of the blame is definitely on us the musicians, but sometimes the stores shoot themselves in the foot too.