Hello I'll be turning an outdoor building into my new coop it has two windows but I know I'll need more ventilation. I'm in Oklahoma so hot humid summers usually cold wetish winters. I read the popular ventilation page on here and she mentioned louvered gable vents and they sounded like just what I need. But all the ones I'm seeing (home depot) are at least 30 bucks for one of decent size (12×12 I believe) is there a cheaper option? I was going to put at least 6 in the coop but that's pretty spendy considering all the other modifications I'll be doing as well (partitioning part of the building off for a feed area and building an attached run and things like that). Any tips or ideas for me?