I keep junk / scrap because that item may have 1 or more parts on it that cost 10 time scrap value of whole machine. When I no longer want it I take it to a consignment auction to see if anybody else wants it. Also if you load up a trailer load of junk pull in to local scrap yard and ask what they are paying you get absolute rock bottom price because they know you don't want to drive another 10, 20 or 50 miles the get another quote. A well attended auction determines fair price.