JW
I work off a 150# vulcan, and there better then a RR iron but there not the best, not a great deal of rebound. I brought mine from a farmer that was going bankrupt, it was in almost perfect condition, no nicks or chips on the face and I paid $125. I would think that $200 might be a touch high for a 100# vulcan but if its in good shape and you need one right away, the little you might save by looking around might not be worth the looking. I would offer him $150 for it, take it or leave it, but thats just my opinion, now if it was a peter wright, you had better jump on it.
If you have a radio station around you that has on the air sales, call in and tell them on the air that your looking for a good anvil, thats how I found mine, after calling in I received 5 or 6 calls from people that had anvils and wanted to sell them, and some times people don't care how much, they just don't have any use for the darn things and want them out of the way. You might pick up a real bargin.
Good Luck
Bill