try a scrapyard, or go to a tractor repair shop, they may have something, but much like your situation, the used one laying around are shot as well. Radiators are priced by overall size and the layers or cores they have, a newer small car my only have at most a 2 core radiator, a Diesel may have 3-6 cores they generate alot of heat like a race car engine. Sometimes you just have to bite the bullet.