I reckon 1kg is a reasonable estimation of weight if the skull is life-sized. There’s no reason to assume he’d buy it by the gram and according to this chart:
it cost $46,691 per kilo in The Netherlands in 2010 or if he popped over to Luxembourg it’d set him back $31k.
There’s an interview over here with the artist where he responds to questions about quantity, cost, fear of legality or police raids with: As this was a commissioned piece, I’m under a pretty binding non-disclosure agreement, and thus unable to provide too much information.
My guess is that this was commissioned by police or anti-drug government body, since no self-respecting artist would risk serious jail time to create an artwork and the fact that it’s “art” doesn’t change the fact that he’s also trafficking a controlled substance.
