I bought a Chinese 1080p action cam for $30 about 3 years ago... is there some kind of competition issue in this market? (and it came with the waterproof case and various mounts)

I'd say there's a competition problem in that there are too many very poorly made "me-too's" that aren't even worth the 30 bucks. The Yi's come pretty close quality-wise to GoPro, have excellent build quality -- and frankly I like the Yi optics better than GoPro's... but they ain't 30 bucks. Disclaimer: I used to design camera systems and used to work in Hollywood so I can tell the s* from the Shinola, so I consider myself fairly picky.

I'm fairly picky too, I tend to compare everything to my Nikon D5100 (maybe not as picky as Q. Tarantino). This $30 action camera has decent image quality but the physical build feels cheap... but it hasn't broke yet.