How to price Audio

I understand if you have something rare you price it accordingly, but what do you price things at?

sound effect, ambient sound, etc...

Search how many similar clips are on Pond5 and price accordingly. I have 2 very unique clips which were very difficult to get and priced them $20
nightingale: (https://www.pond5.com/de/sound-effects/nightingale.html)

woodpecker (https://www.pond5.com/de/sound-effects/woodpecker.html)

Zygis