I am a rescue diver and have some experience with the hairy eyeballs Oxygen supply people (i.e. Roberts Oxygen) give to people who are not on the official medical clientele lists. They also do everything they can to swindle people like me i.e., trading out my beautiful polished aluminum tanks for their cheap-ass steel ones whenever they get a chance.
Cheap-ass is one of my favorite put downs these days. It is accurate!