Sure, the TD Garden is a great venue. But where the heck do you park for a Bs or Cs game?
The recommended option is parking in the North Station Garage.
From the TD Garden’s website:
With the most convenient parking for every game and show, the North Station Garage, located directly underneath the TD Garden, offers a flat event rate* of $38 when you enter 2 and 1/2 hours prior to the scheduled event time. Elevators located in the parking garage will bring you directly to the main concourse in North Station.
There are several garages near the garden, which charge in excess of $30 for event parking.
If you’re amendable to a 10-15 minute walk, the Pi Alley Garage on 275 Washington St. It’s a flat $12 for evening and weekends.
A final option is parking a few T stops away. However, given the cost of the T ($5 round trip), and the fact that parking prices don’t decrease substantially until you get well away from the Garden, it’s not worth it.