Went out last night and picked up all the remaining parts to get these built. I ended up going 3" PVC for the legs. I originally picked up 4" but thought it just looked TOO big and with only an 8" square top plate that would only leave 2" on each of the sides, thought it would look funny.
So far, this is what I'm into them:
Wood: $12.75
Grommets, allthread, washers, nuts, PVC, rubber feet, etc: $22.00
Total: $32.75
Looking pretty good price-wise so far! Now I just need to go and get the wood planed down to size and get it all cut up and sealed. Woo hoo!