[color=#FF0000]::MOD EDIT:: MERGED with Road Bike Accessories thread[/color]
I previously started this thread regarding some accessories and helmets were covered.
Check this post by Ibis [url]http://tw.forumosa.com/t/road-bike-accessories/83077/40
Like he said, stick to the major brands and you should be ok.
I know your budget is pretty high, but just keep in mind that anything under 1000NT will most likely be uncomfortable and not well ventilated. Stay away from those.
I'll add and say that your budget will get you more than you asked for and that's actually great. Your price range will get you something a little aero, light and with good ventilation.
I suggest going to a few shops and trying on helmets. It's tough to suggest a brand and tell you, this is the go to because most helmets fit differently. There's a lot of helmets on the market that are very popular like Giro and the Specialized helmets and seem to fit anyone and everyone, but somehow make me look like I have a turtle shell on my head
If you need suggestions, I myself ride with a well-ventilated Giant helmet, I think the model name is "Race". I was willing to spend 4000NT on a helmet, but the one that fit me turned out to only be 1800NT. I also like ZeroRH+ helmets too, I tried one on and it was 100x more comfortable than my Giant.