It appears that they are still live chips, according to the Chipguide. The casino is still open. As for value, it's going to be on the rare side due to it's location (Namibia), but since not a lot of people will have a connection to the location, buyers could be hard to come by.
10 Namibian dollars = 0.67 Euros (74¢ US), so unless the casino uses something else as it's currency, I'd think it's value is pretty low.