Can I get some webcam advice please?

I've got to video a few hours, mostly outside but some inside in likely dark conditions (a barn). Output I'll be putting online.

Actual video only needs to be 'reasonable', perhaps not even that. No need for high quality, not the purpose.

What's specs or model webcam should I be looking at? I'm seeing two base models at a local store, one's $100, the other's $400. Seems like a big spread even at the bottom end.