The only way I'd try to ship a heavy machine like that is palletized via an LTL carrier. I've seen way, entirely too many sewing machines damaged and destroyed by FedEx and their ilk.
Even then, I wouldn't ship it fully assembled. I'd have that head on its side,strapped like hell and probably build extra supports to keep it in place. Break the table down as much as necessary and give it the same treatment. Then a half mile of shrink wrap around it until it looked like a giant plastic blob. And the selling price would reflect the amount of work it would take.
In truth, I probably wouldn't even try to ship it - I'd do a full court press of local classifieds, ads here, on ebay, craigslist and anywhere I could find, specifying local pickup. Then just be prepared to wait until the right buyer came along. Much better if they pay you in cash, load it themselves and drive off into the sunset than worrying about freight damage.
Good luck with the sale!