Shomer-Tec used to send me a paper catalog back when they were selling APCs for $35k. Their caltrops cost $150 for a 40 pack, which is probably why mom didn't let me buy the APC- those caltrops were never going to be economical for domestic political dissidents. Luckily, China has noticed this market imbalance and stepped in to correct it. "To get rich is glorious!"