Still don't have mine up. Congrats. Looks fun!
Assuming you already have the brew equipment....
Lumber/casters/hardware/paint ~$150
Bayou classic burner x2 ~ $100
i did also purchase a LP tank "Y" splitter on amazon ~$25
i painted it to make it a wipeable surface
5 hrs total build time...
Keeps me outta mamas kitchen and dont have to move near boiling liquid around anymore!