1 old pc power supply + two 120mm server fans from a computer junk shop = $10 and a heckuva upgrade from the stock exhaust system.
It’s not as quiet as the bilge fans that a lot of people use, and it’s kinda funky looking because of my space restrictions, but it moves a lot of air and it was really cheap!
@Jean-Phi_Clerc unfortunately, I don’t have any other pictures of the build. It is pretty specific to my personal setup, so I’m not sure how well it would apply to other users.