[Topless]

Snell does an excellent job of testing every helmet for safety so if it meets the Snell standards it will protect you in a crash. A DOT rated helmet is not legal at most events. It meets basic construction standards but has probably never been tested. Pyrotech and Zaamp both offer SA2005 rated helmets for around $200. Bell has a great product but it doesn't come cheap.

Beyond the safety rating the next question is fit and comfort. I have owned over a dozen helmets in my life from Bell, Shoei, MC, HJC and Zaamp. They have protected my head during some fairly spectacular crashes. The Bell and the HJC always fit my head the best and were comfortable for long events. The MC was cheap and was torture if on longer than 30 minutes. I am sure you can find one with a Snell rating with good fit within your budget.

Most Auto-x events have helmets available for rent so you can try before you buy. Get there early and reserve one.

Good luck in your quest.