The only real solutions to bots and gold sellers is either
a) make the game subscription based, without free-to-play so it’s not worth it for botters to create accounts since they’re getting banned before making enough money or
b) somehow make people stop giving money to RMT sites/stop buying silver/items or
c) make account creation restricted in a sense that everyone has only one account, which is bound to your social security number/ID card/whatever. In korea this system works pretty good. Or
d) make the game cost initial money (say, 30~50 bucks) with no steam-refunds but no subscription fees/tokens/etc but allow cashshop. This, like a), makes it undesirable for botters to pay 30~50 bucks for each bot just to get it banned after a short while, without being able to get the money refunded. Or
e) magic
The most rational and easiest solution would be b), however that doesn’t work because it would require everyone to stop giving money to RMTers/botters/silver farmers. And since there are always greedy bastards who pay real money for items/silver the RMTers will keep coming back.
I can’t really think of anything else, because even if they somehow manage to implement a 100% reliable anti-bot system, the botters will quickly program around that system and reprogram bot progams so they don’t get detected anymore.