i can tell you that ALL of the Sugar Babies made in the world are made in Cambridge, MA at the Tootsie Roll factory on Main St..  
http://en.wikipedia.org/wiki/Junior_Mints
"... Junior Mints are still manufactured in the Area 4 neighborhood of Cambridge at a factory of Cambridge Brands, a Tootsie Roll Industries subsidiary. The same factory makes all Sugar Babies and Charleston Chews."
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The Erotic Highway board is an unofficial SB board that covers all regions. I don't recall a lot of posts specific to Boston, but there has been some info. Post your Q there, too, and it might get some chatter.

I was lucky enough with seekingarrangement.com few years ago, but honestly dating professional escorts way more safer

Try the usual method of seeking arrangements or what’s your price.  
SB dating is overrated in my opinion because yes the girls are young 18-26 years old but come with baggage. Even if you have a per meet arrangement or per month benefits agreement. In my experience they always want more money or have financial instability. More money for rent, books, tuition, car payments or whatever. It was nonstop requests for daddy. And the sex was not that good either. It was as not glamorous as it is portrayed on HBO. No lingerie or makeup or gym toned bodies.  
I’ve gone back to dating high paid escorts. What is the old saying I’m not paying for sex, I’m paying them to leave.