Sounds like a decent deal, of course then you have to mgo through an FFL dealer and shipping...there will be costs added, as should be expected.
I have the Sportster with 3 barrels...long rifle , mag., and .17 HRM...don't know if I would go for the M2....although it may make a very accurate squirrel rifle.
after comparing the .17 HRM to the .22 mag, I can't imagine the M2 as having enough punch to work humanely on 'chucks.
I could be surprised though!