In emergencies I buy kit from such stores - they're all at it.
My tactics are simple and practical. Once I've chosen the kit and physically verified they do have it in their store, I cut off the next hour of "paperwork" sales BS and exasperation on all sides by giving them a simple ultimatum, goes something like:
"I have to go. You have five minutes to do your paperwork and get this box to the cash registers. If this is too difficult, I can help you out by carrying it there myself. If it's not there in five minutes, I'm gone."
The fact that I mean it, and that they can see that, results in a happy outcome every time.
Biting the hand that feeds IT
