Depends on the tractor... A Diesel, 8 speed, with live PTO and PS... 5-6000 if it's real nice. Gas engine will drop it 1000. Lack of PS will drop it another bunch. If it's got a 4 speed transmission... another grand or more discount as that will not have live PTO. Not unheard of for something like that to fall into the 2500 range with gas engine.
The plow... 2-500 depending on how bad someone wants it. Scrap otherwise.