Just a couple things that have been noteworthy for me: Powder coated cookers can be problematic. Some companies do a really good job - some do not. (Rec Tec's powder coating is pretty good).
Design complexity: The Myron Mixon unit in the link above appears to have an awful lot of doors, hinges, cranks,...in other words - moving parts. Moving parts and hot greasy smoke AND powder coating in places that can wear from that movement....present a real potential P.I.A. Powder coating can't just be "touched up" like a paint.
And - that it is designed for grilling - in that the design looks like an enlarged Hasty Bake as another member observed.
If I wanted to budget that approx. amount of money - I would look at the Yoder in this link :http://www.yodersmokers.com/santafe-trailer.html
It offers about the same cooking area, has a gas assist for lighting, is an offset with a firebox that has a grate you can grill on ( if you build your fire below the grate, a fuel storage box up front, and a pot heating plate on top of the firebox.
And - perhaps best of all...it is a Yoder. They are heavy built - and quality of construction second to none. Oh - and...when the paint begins to look shabby...Rustoleum high temp black - makes it look new again!
