PVC lasts longest (rigid pipes that have to be glued together).
"Irrigation mainline" lasts second-longest and it is stiffish but somewhat flexible so it's easier to lay.
I think that Irrigation mainline is around the same price as hoses, but the number and quality of fittings determine the price more than the tubing, unless you have multiple 100-foot runs.
Dripworks sells ½" polyethylene mainline for $16 / 100 feet. That can handle 240 GPH.
http://www.dripworks.com/produ...
They sell 3/4" mainline for $32 / 100 feet, but I've seen cheaper prices locally. (480 GPH)
http://www.dripworks.com/produ...
