I'll follow ye thread, IH. I'm always interested in this slab vs. pier debate. I'm needing a new bigger barn, and not wanting to go slab either due to cost.QUOTE]
There is no cheaper way to build a strong building then pole barn construction. Setting the poles in the ground and installing purlins for the walls is a time proven, cost effective and easy to do method that is very strong. Installing trusses or putting a post in the middle and installing beam the length of the building so you can go with rafters is the same for anytime of building, so that's a push. Not having to put in a foundation, or grading the land, means huge cost savings in time and materials. Adding gravel at a later date is also the most affordable flooring to have, but it does mean dealing with rocks that work their way up and not having a perfectly smooth surface to work on. For just storage, it's great.
The reason I suggested that the OP go with concrete is that he was creating a fairly complicated foundation for his barn that would be less complicated with a much better surface if he just went with concrete.
Eddie