Looks rather cheap by Boston standards. No one goes by monthly rates
here; its always quoted by the season. Rates for the 6 month summer
season is well over $100 per foot for all of the marinas close to the
city - $140 in several, $180 in the fancy one downtown. Even the
"less desirable" marinas have crept up in price as they got filled and
are now over a hundred. Plus most carefully measure and charge for
the bow roller or davit, or charge for what the slip is "rated for."
Electricity is metered, live aboards get extra fees, etc.

About $150/ft in Annapolis, but our electricity is included. It's a
year-round slip if you wanted to leave it in, but we have ours pulled for
work and winterization.