We went through this 7 years ago in NY.
Roughly speaking, our options (building only) were:
*stick built $80K
*prefab $65K
*pole barn $50K
We went pole barn and we are happy. Guy we hired has done 250 of them over 40 years. You save as there is no foundation - you sink the poles, build up the building on the poles, and pour the floor at the end.
24' by 24' with an upstairs (unfinished). We put in lots of bells and whistles (doors/windows that were better than average) and electric added to the cost, but we wanted to keep it under a certain number...