For about the cost of two tires, it looks like either STIDA or Competitive Advantage would be great coverage to have. Hospital costs are crazy these days, unfortunately I experienced a few non racing trips to the hospital and the bills would have been staggering without insurance.
The exclusions and restrictions written into most insurance policies may make it pretty risky to rely on your "normal" health insurance. Not to mention life insurance, disability insurance, etc-those you usually need a rider (more $$$) to cover racing, riding motorcycles, skydiving, scuba diving and other fun activities...