They could not be bought in the Elite Gear catalog from January 3, 2019 to September 26, 2019, since there was no way to earn EPF Medals. Currently, due to the re-opening of Field-Ops, they are obtainable through this method again.
When you find the Dark Vision Goggles in The F.I.S.H., they are priced at 1000 coins. However, when you try to buy them, they actually cost 10 coins instead. In addition, they only remove 10 coins from your balance.