It is not just the weight. How are the corners of the anvil, badly rounded chipped, is the face flat and smooth or has someone gouged it. Same thing with the horn. Lots of these can be ground out or repaired, but, decrease value. Is the thing all steel or laminated, and lastly who made it. Some anvils have increased value because of their makers. I put out a sign at my booth in a street fair. I got all kinds of interesting stories about how this or that anvil got buried, hauled to the scrap yard etc. I finally got a nice 110 # steel anvil for $100 and a nice Sunday drive. Anvils are around. Most of them sit ignored by their owners. I also searched on Craigs list for a long time. Shortly after I got mine 2 more appeared. Bigger and for about a $1 a lb. I think a key to a good anvil at a decent price is patients