Needed some blocks of limestone edging for a lawn project. A 4 x 4 x 14 inch block goes for about $3.50 at Lowes. They weigh about 17 pounds. Driving home I saw a landscaping company with a big yard full of hardscaping materials. I called and they said they sold to the public and limestone goes for $350 a ton. I started to calculate cubic feet and before I got too far I realized it was easier than that. Lowes was $3.50 / 17 lbs = $0.20 per pound. The landscaping yard was $350 / 2000 lbs = $0.175 per pound. Probably just going to Lowes.