I need to move a 12x12 shed approx 3500 lbs about 30 feet back. Thinking on using sch40 pipes and 6x6's with a come-along. 3" Sch 40 Pipe... more because its lightweight, cheap and convienent. Any recommendations?

Probably work.

I think I'd use schedule 80. Thicker walls and not much more in price. 1.75 tons is a fair amount of weight. How are you going to lift it? I'd also consider rolling on OSB or Plywood, piping may sink into the ground.

I think it should work. Lot easier? Hire a tow truck to pull it part way up onto truck and move it and slowly drop it off. They only have to slide it about 1/2 way on truck, if it is lifted and braced at middle, they can often slide the bed up under. Most may only charge you a couple hundred dollars if y