I had been looking for that barrel myself last year. Unfotunately, the cost was so high I wound up getting another gun alltogether.
Surprisingly, after much searching, I was at my local Dick's and they had a notebook of all the guns and accesories they can order on the counter and I started looking thru it. I dont remember the cost, but I was absolutely surprised that they can order the barrel and the cost was alot cheaper than any other place I had found.
I asked the guy at the counter and he said that they do special orders and that he could probably get the barrel for me in a short time period.
So...it may be worth a shot(no pun intended)