I'm currently starting a 40'X60' panel building. I've been getting quotes for about $15K-$17k for the building itself (no interior finish) using 2 12'x10' doors with 12' walls. But the concrete is going to cost me a lot more. I have to build on an unlevel site, and decided to do a 40' x 30' basement with suspended floor above. There will be a 4" flloor in basement level, 6" suspended floor with lots of rebar, and 5" slab floor in front. Concrete will cost nearly $25k. Around here (Southeast MO), the Morton buildings look a little better, but cost a lot more!