This might not be a new concept, but this is what I came up with.

I went out and bought 3/8" cable(@ .69/foot) at 6' lengths.....2 cable clamps per cable (@ .49 per clamp)..(the ones that have a horseshoe bolt that two nuts go on) and a big Masterlock. Make a loop on each end of the cable with the cable clamp and tighten the heck out it. Then I had a buddy tag weld the nuts on the bolt so they won't ever come off no matter what. The masterlock at around $5 a pop and then about $3 for the cable and clamp. I don't think anyone is going to be able to get through this baby unless they have some industrial size bolt cutter. The whole setup is much cheaper than chain(which most people can cut through with ease) and is almost rip off proof. What do ya think?