Bought this one yesterday, Vega Nitro NT200:
http://www.vegahelmet.com/nt200.html
Also includes a clear full face visor to use instead of the "upper visor"
Paid $50 from a dealer going out of business. Love it, it's lightweight, comfortable (I normally have to wear an XXL full face helmet, this one fits better in XL). An open face helmet is a huge difference from a full face. I can hear every noise the bike makes, less wind buffeting, it seems and generally cooler (temperature wise).