Be careful about equating the price of a helmet with safety. Will a $1000 Shoei helmet protect your head 10 times better than the $99 HJC helmet? No. Both are going to be certified to the same DOT and Snell standards.
The difference in price is comfort, fit, paint job and name recognition. If you are only going to be using the helmet once a year for LSR, there is no reason to pay extra for a premium helmet. Buy a helmet that is certified to both Snell and DOT, and fits you well. If you want everyone to be impressed with how much you pay for a helmet, buy an Arai or Shoei.
Don