Even at the dollar store!
If you can’t pipe your sound into your camera, borrow a camera with a microphone jack and use that to record audio. There is no real difference between a ’spensive 16-bit digital recorder and a 10-year old Handicam that records sound in 16 bits. Except, well, cost.
The funny thing is, that one can spend a pretty small amount of money on even marginal sound equipment and it’s going to be better than the default junk.
I was amazed to see $1 microphones at the dollar store, but I’ll bet those are better than the typical camera-mounted microphone.
Guy at a local shop kept telling me great 16-bit recording was, and I almost bought a very pricey recorder, until I looked at my old Handicam and saw that it could record 16 bits of sound. Were those… inferior bits?!
These days, I prefer either using cameras that have sound jacks, or doing projects where synchronized sound is less of an issue.
In retrospect: I still try to cheat around sound sync, but at least I’m not super worried about it anymore.