Because a lot of glassware is not easy to clean and manufacture, like beakers, flasks and tubes. A lot of lab glassware involves complex joins. Condensers and

Because a lot of glassware is not easy to clean and manufacture, like beakers, flasks and tubes. A lot of lab glassware involves complex joins. Condensers and refluxers have tubes in tubes with edges that are not even accessible. There may be reasonable arguments to use some of the cheaper glassware once. I know I have chucked glassware instead of cleaning it. Specially if I used it for something I never want near anything else.