Hi sbshaver,
I had my manufacturer put my roof vents (2) in and wire for the fans (they are great in warm weather or to vent the trailer). If the $175 includes a good quality vent with fan & wires it, and he welds in the braces, the $175 doesn't sound too high to me. Mine went in at time of trailer manufacture; I swapped the side pass-through vents for one ceiling vent with fan, and paid $90 to put the other one in. Both have welded in bracing to support an A/C if I ever chose to install one and are wired with fans (Not the fantastic fans and are not as efficient and a bit noisier.
Here are the way the mfg put in my ceiling vent braces ...
gallery/image_page.php?album_id=3168&image_id=111064Call a couple of places and good luck to you ...
