We have always and continue to shop material cost each time we buy. It is the only way you can keep your supplier honest. We never charge our materials we pay when they are delivered. My brother, years ago go upset when he received a paid invoice of ours from a supplier, we both used. He was buying the same product, 920BR ballast. He called me upset because he was paying $23.10 and we paid $8.60 for same item. He bought four we bought a full case of twelve, we paid when... (more)