How can I watch Celtics and Bruins games the most affordably?

The '22-'23 sport season is a real lure for Boston sports fans as the Celtics are title favorites and the Bruins are off to a historically strong start (17-2-0 and counting OMG!) As a true band-wagoner, I'm eager to follow our overachieving local franchises, so I'm appealing to my fellow fans how to watch both Bruins and Celtics games in a way most affordable for a retired person who, a.) doesn't want to pay ransom to NESN ($399/year! and couldn't care less for dysfunctional Red Sox baseball), b:) doesn't want to pay for two major streaming services (YahooTv doesn't carry NESN and NHL network, FuboTv doesn't carry NBCSN (Celtics), TNT, and NBATV.
Any suggestions?

FanPosts are fan-created content and do not necessarily reflect the opinions of CelticsBlog. Be respectful and keep it clean. Thanks.