A lesser-known gem of a supply catalogue is American Science & Surplus. They do have three retail stores; two in Illinois and one in Wisconsin, but their main business is on the internet.
The product listings change often, so if you find what you need it is best not to hesitate. Product categories run the gamut from sets of artist-quality brushes, test tubes and Bunsen burners, electrical parts and household items. Everything in the catalogue was a surplus item and offered at rock-bottom prices, an educator on a budget's dream.
A fun aspect of this company is the highly entertaining ad copy their creative writers compose to describe products for sale.