I read in one of the motorcycle rags a while back that most all helmets with DOT/Snell approval will protect your head pretty much the same - some of the cheaper ones did better than the expensive ones, IIRC. Where the money is spent on the Shoei, Schuberth Arai and other "high end" helmets is in the fit, finish, farkles, and grade of materials used. Do you really need a carbon fiber reinforced helmet that will protect your noggin up to 150,000 Joules of impact energy, when your noggin is going to end up in your boots at anything over 1500 Joules? :roll: I know I've got the numbers off, but that was the point of the article.
The most important factor in choosing a helmet is fit. If it's not comfortable, it's either going to curtail your riding or distract you, which is unsafe. Try on a lot of helmets and DONT LOOK AT THE PRICE TAG BEFORE PUTTING THEM ON. Base your decision on fit and comfort first, features second. Don't worry about the price AT ALL. It's the most important piece of gear you will own, so take out a loan if you need to. Hopefully (like me) you'll be pleasantly surprised and it will be a less expensive helmet that fits the best.
Scorpion, HJC, and a miriad of other manufacturers are out there. They all shape and pad their helmets slightly differently. Take your time. If you find one you like, wear it around the store for at least 20 minutes to make sure there are no "hot spots". Good luck!