Thank you all.
I figured out the NH angle after posting. I found a dealer in that state willing to match the Boston price.
Its a Volvo XC90, 5 cyl, all packages.
Best price in Canada: CAD$58,650 plus taxes
Best price in NH: CAD:47,750 after 6.1% duty and exchange, plus taxes of course.
(If you buy an Acura MDX, there is no duty because the car is made in Ontario).
Worth a five hour drive and a $250 fee to hire a broker to do the paperwork.