I need addon for checing inspected element and alert on change

Hey guys
I need an addon which check an inspected element on the page.It’s a number and I want to be notified when that number goes bellow a certain number.
it’s changing constantly and it has commas.
Is there any addon to do that ?

SiteDelta Watch | https://sitedelta.schierla.de/index.en.php

Update Scanner | https://github.com/sneakypete81/updatescanner/ | https://sneakypete81.github.io/updatescanner/

… Due to changes in Firefox, Update Scanner has been completely rewritten, and not all of the previous features are finished. …

I’m more familiar with SiteDelta Watch. Began testing Update Scanner a couple of days ago.