I just emailed CR Pipe. Here is what they stock. They're Cliff Carroll Anvils, so pretty nice ones.
35 lbs- $205
70 lbs-$385
125 lbs-$650 (Just a few of this size in stock at the moment)
Not to hijack the topic, but is there any concern with accidentally striking a sledge hammer head (which I presume is hardened) with a hammer (which I KNOW is hardened?)