There's really not a place local, if he wants to try on some helmets I think he's going to need to travel a bit.
The last time I bought a helmet was 10+ years ago, and I think I went to turner motorsports. Even there, there was like 2 options that were somewhat affordable, and one fit pretty well and the other not at all, so it was pretty limited still.
Now 10 years later I need a new helmet, I'm just going to stick with the same manufacturer HJC, mainly due to the fit and price point is still good.
Where are you guys located, I live on the south shore