I did break down and buy a plant at auction for $280 from Steve's Leaves which included tax and shipping in winter. But in my defense, I have been looking for Black Maranta since I saw one in 2008. Even back then it was expensive if it ever came up for sale.
This is what it looked like when I got it. The Silver Band I bought on Etsy at the same time was for a lot less but still more than I would normally pay for such a small plant - about $40 without tax and shipping. The Etsy plant had a lot less root development, died back a lot and struggles still but is steadier now. The Black Maranta has great roots and hasn't skipped a beat.
This is what they looked like after unpacking.
Do you come across Black Maranta at all?