Arai makes a good helmet. I probably look stupid, but I wear a $500 Arai when I ride my $600 motorcycle. I really like it, but when it needs replacing, I'll probably find something cheaper. They stopped selling over the internet, so you pretty much pay retail for one now.
I also have a Shoei and a cheapie M2R helmet. The big difference between these and the Arai is the weight. I had to use the Shoei for the first time a couple of weeks ago, and I could feel the additional strain on my neck. Of course, if that's all I had, I'd probably be used to it.
Motorcyclist did a big writeup a couple months ago and concluded that the cheap helmets work just as good if not better than the pricey ones. The only tradeoffs I can see are the weight and comfort. Look at some of the Nolans, AFX, KBC, THH, Icons...etc out there and see what feels good.