For being a consumer grade cam, the T series of Canon DSLRs does very acceptable video and has a mic input. I’ve shot some pretty decent stuff on my old Canon T2i (I modded it with Magic Lantern firmware for extended features, but it was good by default). The newer gen ones are even better and easier to use. The quality isn’t quite as good as the full frame cams but, for web promos, youtube, etc., you’ll get a professional grade look if you shoot properly.
The $500-$800 would be a good investment, considering you’ll also have a very solid photo camera. And it couldn’t be much easier to use. Good luck.
