Any AH Hirsch at $50 is a great buy. I have some bunkered and I'd buy the lot if I found it at this price. That said, I wouldn't trade any Pappy 15 for it let alone a decanter set.
Bottom Line: You made a good buy. Now you just need to decide if you want to drink it or barter, and if you barter, do you prefer quantity or quality? This is pretty much your only chance to sample it at that price unless you find a bar with an open bottle. But if there is something else you have been dying to try this could be your opportunity.