Rails

costs were going to be
8.50= pvc
.65= metal rebar (each)
3.00= sand
4.00= stakes
2.00?= 2 screws (long) for anchoring

total around $20 depending on how many metal rebars you can fit into the pvc pipe

I dont work with PVC alot exept when i first started, i will say metal is better but PVC is great for learning. The PVC wont snap if you get some that is about 3' diamiter, it will only bend, for leg supports i would get a T-peice and cut off the top half of the T so it will attach to the rail then drop the leg from that. You will probably want four legs if you do that but keep in mind 8ft isnt that long so if you left a foot and a half on each end that leaves 5 feet in the middle, just kind of experement.
Striker Productions
Missoula MT

when i was in 6th grade we would make our skateboard rails out of PVC, to make them so they would not break you cut out a strip 2inches wide down the whole lenth of your pvc pipe, and then wedge a 2x4 into this cut out so that the 2x4 touches the innerside of the side your going to slide. Then you can attach this to whatever you think works.