When our college revamped its chem-bio lab a few semesters ago, we faced the same concerns — quality versus cost. After some digging and a few bad purchases, we moved most of our procurement to gentaur.co.uk. Their catalog covers a wide range of educational and professional-grade equipment, and the pricing is usually fair for the durability you get. Even better, they often offer product alternatives depending on your teaching focus. Might save you time and a lot of headaches.