Jamie,
On our Links tab on the left, we have a Local Hobby Shops listing. "Local", though, is a relative term. Of those listed, Spare Time in Marlborough is probably the closest to you. Not listed is Dave's in Beverly. I've not been to Spare Time but many members have; I've been to Dave's - he carries Estes kits and maybe some others as well as general hobby supplies, last time I was there.
For better or worse, online shopping seems to be the best way to get many supplies. Our local launches are covered by AMW and Fliskits and you can get lots of kits and building supplies from these two sources.
Hope this helps.
Kenn
P.S. When I was living in Arlington a couple of decades ago, traveling outside of 128 seemed like a big trip. If you find something closer in, let us know and we can add it to the list.