For free, maybe. Depends on what other things demand your time.
I have been involved in several of these "projects", something of a sport in my family.
The latest was a 60x144x14 Morton used as an indoor riding arena. We moved it 90 miles, it
is now used for equipment storage on my farm.
Some thoughts:
1. Put the steel in some nice bundles and take it to the local agricultural focused consignment auction. Several enterprising souls will
gladly bid 50% or more for it. Then purchase new steel.
2. Don't pull the ring shank nails holding the frame together. Instead use an angle grinder to knock off the heads and then pull the lumber apart. Then snap the remaing shanks off with a hammer.
3. Don't put the poles back in the ground, use perma-columns or stem wall mounting brackets. In our area a wood post will last 40-50 yrs. Buildings I helped put up as a kid mother nature is now bringing down. Several neighbors are preemptively taking sheds down so they won't have to chase parts all across the farm when the wind does the job.
4. For any first time project take your best estimate of time required and multiply x10. We have become pretty efficient but have many projects under our belts and the equipment to do it safely.
I came across a 40x60 pole barn for sale. From the pictures it looks like its in pretty good shape. Metal siding all looks straight, decent roll up doors. I would need to dismantle the building and move it, then reassemble on my lot. The price is $22k.
Is it worth the hassle? I have never dismantled a building with the intent of putting it back together. I have also never owned a pole barn. Are there things I should look for while inspecting it? Are any of the pieces "one time use" and would need to be replaced with new?