We camp on the Ohio River for the entire season and we wanted a deck to keep everything up off the ground, but I wanted portability too since the area is prone to flooding in early spring. I priced up building 3' x 8' sections of wood decking and for my $200 budget I wasn't getting much deck. I found some pharmaceutical PVC skids/pallets that are flat on top and 48" square that we will be making our new deck from. Just place them all together and I now have a 28' x 12' deck in front of the trailer and it's easy to move out at the end of the season. We plan on putting down an outdoor bamboo rug to cover most of it.
I placed an ad on the craigslist wanted section and got lucky when I got a response from someone working for a company that we happened to do a lot of business with and got my skids for $10 each (half of what he was asking), I ended up buying all 69 that he had for myself and some fellow campers. My parents and my gf's parents lucked into an even better deal about 2 years ago and got a different skid with a small open hole pattern for much less, about 50 skids for $100. I will admit it was not easy to find what I wanted, it took 2 months of searching but I am pleased with what we ended up with. I'll post up a pick in few weeks after I get the rig to the river and everything set up.
One other thing to keep in mind is storage. We are lucky enough to have a family member with a large barn where we will now be storing almost 150 skids for our group over the winter months. The nice thing about the PVC is you can leave them out in the weather all year.