Recently all EB Games stores stopped stocking gem cards and today I've confirmed with them that they are discontinued in all of Australia. As an Australian player (and one that has been playing since launch) I'm really disappointed to learn that I can no longer purchase gems locally.
You might say "Just buy them from the online store", but the exchange rate from US to AUS dollars is ridiculously high and has been for a very long time. With physical gem cards, we would purchase 2000 gems for $25AU. Now our only option is to purchase 1600 gems for $36AU or 2800 gems for well over $50AU with the exchange rate constantly fluctuating. Gem cards have been, and still are, the best value for us in Oceania.
I don't know whether ArenaNET discontinued them worldwide or just for Australia - but I urge you to help find us a similar solution or we're not going to have a choice but to stop purchasing gems altogether