In my experience working in a remote team, what matters is the audio. Ideally a headset (so that your voice does not get cut while someone is talking) with a decent mic. Not understanding what the remote person says is very frustrating.

Any webcam does the job as long as you can recognize the person. Anyway most people use this blurry background thingy, I really don't believe that the video quality matters.

I agree with you that if you're doing a lot of remote interviews having a decent camera is worth the investment. I have no doubt that people will subconsciously judge people who have meet through a potato.