the people at hardware and lighting supply places WILL notify the local authoritys when a purchase looks suspicious.

This is extremely rare. Most places don't care what you buy from them as long as you are spending money at their establishment. They want you to come back, and most people won't if some place reports them to the authorities for buying legal stuff. After all they sell it. It would be pretty hypocritical to "tell on someone" because they bought stuff you are selling.