What should I be looking to pay for a small custom plenum box like this?

Hey guys, appreciate any advice. I'm looking to get a custom plenum box done to use as an airbrush booth. I talked to a guy this morning who seemed like he was trying to take me for a ride, wanted 5 hours at 130 an hour to build it. Just looking for a realistic idea of what I should be paying for a box like this https://www.gattoworks.net/html/upload/save_image/0821104157_64e2c0e51cf09.png

Basically what I'm looking for is a 2foot wide, 1.5 foot tall, 1.5 foot deep plenum box with, with a baffle inside, and a 6 inch collar/or hole so I can put my own collar for a fan.

What should I realistically be expecting to pay? How long does it actually take an experienced guy to make that? Does a small box with a baffold really take 5 hours to build?

Appreciate anyone who takes the time.