Perhaps in the future we will add more artifact barrel's however we would like to have different currencies for each because not all artifacts are created equal.
I was thinking about that last night and yes due to the random nature of artifacts and how some of them drop having different turn in barrels and currencies would be best.
As a side note i considered adding the ML minors to this barrel but decided against it last minute. My general thought was 1) this was requested but more importantly 2) get people to start hunting on what is more or less a dead map. I think Dante and Kyn gave a very huge incentive for players to hunt paragons now with this turn in. This also filled a secondary request of giving a non-fel method for getting 105-115 power scrolls with vendor stone purchase. If we allow any artifact to be turned in for this currency it will dilute and possibly destroy some of this.
my 2 gold pieces anyways