I have 2 pole barn buildings. One is 32'x64' and the second is 45'x18'. The larger building was on the property when I bought the acreage in 1987 and I built the second one about 15 years ago. If I remember correctly, this building was about $10-$11K with 30 amp service (which I totally installed/wired)and a gravel/lime based floor. I'm guessing it would cost more than twice that amount, even approaching $30k with a cement/heated floor today. Good luck, I certainly wouldn't be without my buildings!
Days camping (2015)----88 days
Days camping (2016) ---110 days
2016 Wildcat MAXX 28RKX (33' TT), 2007 13' Scamp
2015 Ram Laramie Hemi
30 years RV'ing
12 different RV's