They are still readily available. My feeling is that there are more available than people looking for them. That said, they still bring a premium because it is a beautiful medal in an impressive size. I'm still looking for the 3" silver version. Only 100 were made for ANS members.
Earlier in the year I found a Hudson-Fulton item that I hadn't seen before, nor was I searching for. I have an eBay search for such items. I am now the proud owner of a Hudson-Fulton Special Edition Zither. No, I can't play it and have no intention of learning.
I've been waiting to post this until I knew that it was in route to me. This is my white whale or holy grail acquisition. Since I started collecting Hudson-Fulton I have been looking for the 3" silver medal. I have never seen one for sale. These were made exclusively for ANS members. 100 were made. The only medal of the series more scarce is the gold medal. This one finally showed up on eBay earlier in the week, and it even was available at a reasonable buy-it-now price.
Over the last 6 months I have been able to add a couple more elusive varieties. This August I will be displaying the collection at the ANA's World's Fair of Money.