My brand new LQS is great. They use a ruler and rotary cutter and make sure you get the whole amount, and wee snick more.
If I am in my local Joanns, I love it when the one male employee is working. And I don't mind if I have to wait a bit in his line as he takes his time to make sure he is being very accurate, and he leaves that wonky bit on the end of the cut. After all, if the end showing is wonky, you KNOW the whole bolt is likely wonky, so with that extra bit left on, you usually can get what you need from your piece.
Patti