The following is a write-up to make your very own Cheapstacle. The name is based off of Slug's Mobstacles. Below is a quick materials list and price comparison to the mobstacle.
For 1 Cheapstacle:
-10 feet of 1/2" PVC (I can get mine 1.99 as long as it's SDR 13.5 [thinwall])
-12" plastic tent stakes (6 for 5.49, so 1.83 for 2 stakes [2 needed per Cheapstacle])
-Plastic tarp (I think it was 18 for a 10' x 25' tarp, and I with my size Cheapstacle I get ABOUT 17 per tarp, so .94 per Cheapstacle
-2 PVC elbows (50 cents each, so 1 dollar per Cheapstacle)
-1 PVC coupler (50 cents?, I forget the actual price, but I'm guessing it was as much as the elbows)
-Screws and nuts (I just had these lying around, this is probably too much, but I'll just add a dollar per screw and nut, if someone knows how much the sized ones I used actually costs, do tell)
So per Cheapstacle, that's a cost of ABOUT 7.26, compared to 12.45 per Mobstacle. Something to consider, though, is that Mobstacles have 3 segments while Cheapstacles have one. Actually, after reading Slug's write-up, his are actually cheaper per segment.
In other words, just view these maybe as an obstacle just thrown together with various crap, as the cost for Slug's isn't that much different per segment. It also really depends on how big you make them. I think I'll keep then name Cheapstacle just because they LOOK and ratty compared to Mobstacles. Enough bullshit, onto the write-up.
Grab one of those fatty stakes.

Sand it down so it can fit into the thinwall PVC, and make sure that its a tight fit.

Slide it into a 5' piece of PVC, and then hammer it in as far as it will go. If you sanded it just right, it should deform the PVC and make large lines in it, which also means its well in place.

Drill a hole and fasten a screw through it.

Now do the same thing with another 5' segment of PVC
Now hammer one of the poles into the ground. Cut off excess PVC to get the Cheapstacle to be the height you want it at. Cut at the same spot on the other pole. Connect the two cut-off pieces with the coupler. This will be your horizontal bar. Cut out a piece of plastic sheeting. Make sure its larger then the assembly so you have room to make it so the PVC can slide into the sides.

Start folding the tarp over a bit and taping it down. This will make it so the PVC can go through it. Start with where the horizontal bar will go through.

Cut out the two top corners to allow slots for the vertical poles.

Make slots for the vertical poles.

Here's everything ready to be assembled.

Assembly video.

Finished product.

Final Notes:
This didn't end up being as cheap as I had planned. A couple ways to make this cheaper and make it actually worth doing would be to buy everything in bulk online, and NOT at your local Ace. The fittings I bought were in singles.
Edited by TantumBull, 29 June 2009 - 05:44 PM.