I already submitted a ticket, but I've completed all the commendations but that title shows 17/120. I'm thinking it was at 0 at the start of the day and I've blown up 17 skeletons today. Other people I played with could just buy it for $0 but it's locked for me.
Edit: Okay, I got it. Even though it shows it as unavailable in the commendations you can buy it from the Bilge Rat Rep for 0 gold.