When you get up into the $500 range, why not just buy a new blacksmith anvil from Mankel Forge? I searched for a long time and found a bunch of nice used models, but most of the good ones were in the $350 - $400 range. I got the Mankel #135 shipped to the west coast for $540, delivered.
This is not intended as a criticism or a flame, just a question about anvil value. The new Mankel was in perfect condition for roughly $150 - $200 more than the best Peter Wright, Vulcan, Trenton and other anvils I found. I have used a number of old anvils and found little or no difference in rebound and "feel" between the new Mankel and the older anvils. Is it just the allure of the past or saving a few bucks? It just seemed to me that newer was better since I never had to worry about hidden cracks or other deformations, nor whether the anvil had been through a fire. To me, new was better.