How about Green Harbor?
Neither had I!

But this small, busy port is famous this week for having the cheapest fuel on the coast of Massachusetts!

This is a sweet harbor and beach community that no one has ever heard about! They even have a Safe Harbor (brand) marina a bit further up into the harbor.
There was no room to anchor, and no transient mooring balls. So, after taking on fuel and ice, we headed to the Plymouth-Duxbury Bay area and anchored in behind Clarks Island.
We have not paid under $5 since back in April in NY. (Only paid over $6 once! And that was by mistake. We had pulled in and fueled up as this other marina’s advertised price per gallon was very low. However, the outfit did not include tax in their advertised price… something that everyone else does. Very Shady.
(Naming names: May 22, 2022 at Safe Harbor Onset Bay, south end of Cape Cod Canal). Advertising low fuel prices that do not include tax, (to make them look lower). The customer does not find out until AFTER the fuel has been delivered. Not cool people!