I built mine, the one you've lookin at from scrap that I had laying around except for the thermo and shelf on the right and maybe a couple of other small things. But this one that I built to sell, I had around 300 in material alone. If you go to the link that I put below the pic and see what's inside, I think you'll understand why so much.
I also forgot to mention that both of these units can be used as a grill. The grilling grates are also adjustable for height for different temps.
Here's a link to see the build. There are 2 pages of pics here.http://s99.photobucket.com/albums/l3.../New%20Smoker/