I just built a 12x24, but it's a little nicer than most think of when they picture a shed. Finished inside with power, insulation and HVAC. My total price was somewhere around 12k. The inside was around 4-5k of that. Could have saved a little money by going with cheaper siding (I used Hardi board) and lumber prices have gone down at least 10% or more since I started the build (last October).