Gather labels (a couple of words) from list of sites

I want a label/phrase, most of the time a couple of words, gathered for 500 sites. You task is to go to the site, open posts on the site and look for the phrase (only one phrase) and copy it to excel sheet. The phrase has distinctive feature and easily recognizable but you might need to search in few posts to find it. I'll give you more details in PM. Max budget = $35