barter off
To relinquish ownership of an item by trading it to another person. A noun or pronoun can be used between "barter" and "off." I didn't need that old piece of junk, so I bartered it off. I can't believe you bartered off your car in exchange for a few old records.
barter something off
to get rid of something by trading it for something else. See if you can barter that old desk off. She bartered off the used bookshelf.