I went down to the local Cycle Gear and tried on several Bilt street helmets. I wear an XXL, and every one of them was too small. A couple of months later I was ordering some stuff from motorcyclesuperstore.com, and decided to order an HJC CL-16 in XXL, figuring I could return it if it did not fit. Turned out to be one of the best fitting helmets I've ever owned.
I won't spend more on a bike than I think it's worth, but if it's a good deal, I don't seem to have a problem buying bikes I don't need.
2002 Vulcan 750, 2013 Royal Enfield B5
2001 XT225, 2009 Genuine Stella
1980 Puch moped