Hi Jon,
I looked around for a booth quite a few years ago and gave up because of the prices. Now,the prices are higher than ever.
I solved my problem by building my own. It's really easy. I used a kitchen cabinet that I found along the road on trash day. Cleaned it up. Put an angled furnace filter in the rear. Picked up an exhaust fan for $70 and a drier vent. Mounted the vent on a board that goes in the window when needed. When done, the board comes out of the window. My wife made a combination curtain/filter out of a piece of sheer curtain material. When I spray, I open the curtain. When done, I close the curtain but leave the exhaust fan on to help drying. The curtain also acts as a filter to keep the dust from getting on the freshly painted model. Over time, you will see the curtain start turning grey. That's the dust that would have settled on the model. When it starts looking grey, just take it off and throw it in the wash. The inside furnace filter usually lasts about 6 months and runs about $3 at Lowes.
Below are a couple of pics of my set-up.
https://photos.app.goo.gl/nTF6iw6q7VFqpXUb8
Hope that this helps.
Stay safe.
Jim 
Main WIP:
On the Bench: Artesania Latina (aka) Artists in the Latrine 1/75 Bluenose II
I keep hitting "escape", but I'm still here.