I can’t compete with Steve, but this thread has a photo of my small work area with a booth I built myself. There should be a little discussion in the thread about it. Basically, I built a booth using foam-core board and muffin fans:
It’s much larger than the cheap ones I could find online, and it has a higher air flow. I’ve got most of the stuff to duct the fans out the window to the left, so soon it will be suitable for more enamels and lacquers.
I have the plans that I hand-sketched somewhere, if there’s interest I’m sure I could find them. It’s pretty straightforward, everything was cut “flat” and then where support was needed, I folded a triangle (look at the “face frame” and notice it’s integral to the sides) to provide strength. Pieces are all duct-taped together. All-up cost with fans and lights was probably around $100, with 75% of that being the fans and the lights!
A standard sized air filter slips into place, and the fan plenum in the back has a divider to split the space for the two fans, so each fan draws from one 12"x12" opening. Self-adhesive LED light strips provide plenty of lighting for any work I’m doing in there.