Thanks for sharing that article. I wasn't able to find the total number of them either but it seems, as you write that it is 12.
$1M is a lot but keep in mind that the bronze alone comes in at around 120 per kilo and so that's around $100,000 just in material. Then there is the artists work, the foundry costs, the shipping etc.. $1M isn't what it used it be. Heck, with the new SMT announcement I might even become a Steemit millionaire! :)