Is NPWT similar to 拔火罐 in China? It also creates a near vacuum negative pressure using hot air. It's been practiced for thousands of years. And it also costs about 3 dollars, in RMB.
I think it differs in that fire cupping is not traditionally done over an existing open wound but rather specific locations on the body (neck, back). It might be a cheap way to do NWPT, but it would be hard to apply to uneven or bony areas like joints or hands/feet.
