I pay what the only two stores in a reasonable distance charge.
Try doing some online shopping. If you're buying high-end gear, I'd say that was probably reasonable, but you can get a good-quality WTF head protector for under $40, etc. For what it's worth, we retail a full set of TKD gear for $150.
In other words....liability.
Sure, liability is a part of the cost of running a school. My point was that the liability cost for a TKD school is the same or less than for a BJJ school, so that would not be a reason why a TKD school would be more expensive.