Gshock’s website. I got an email for it and figured I would give it a shot (since I never win anything). It was a ‘contest’ they had open for a few days to have the privilege of buying one. Here’s a link to it for more details (not sure the syntax to make it a clickable link, so I apologize in advance):
https://gshock.casio.com/us/products/collection/limited/dw-6900nasa23-7/
Good ol’ EBay!