Long time experienced botter here
For people who say that more money is possible than cata, not really, I have multiple accounts across multiple realms and let me tell you mats are dropping insanely quick, way way faster than cata, you know why? have you even seen how many nodes you can hit a day?? There is so many veins of ghost iron ore across pandaria and herbs it is INSANE, but with how fast mat's are dropping and how much materials you have to shift every day it gets harder and harder each day to make your gold target.
Also people have an exceedingly bad common habbit of selling way too low, the Chinese flip the shit out of your gold, when they buy for $0.5, they will sell on for $1.5 with ease and that's at lowest prices, but hey continue to sell at that price right? fuck us all in the ass as the chinese know that even if you decline $0.5, the same day someone on your realm botting will sell at that price anyway making your decision to decline completely void. They will offer you god awful prices for your gold as soon as you ask because one of you is stupid enough to take it, it's been like this for years, I guess the fact that quite a few botters aren't from the richest countries and will take any money they offer as well, the rest just have piss poor business and bargaining skills and most of the time don't have a clue what they're doing when they sell gold.
I have heard about this duping rumour also and I think honestly this has played the major culprit, anyone who has been here for multiple expansions knows that gold just doesn't fall this fast, combined with the fact that GB2 was total shit for the first month of the expansion leads me to believe that gold was coming elsewhere and this has to be the cause, blizzard really need to come down like a ton of bricks on this method or goodnight sweet money.
Also private buyers, go get some, I'm not saying I have an extremely huge customer base for every realm I'm on because I don't but if you really want to stick your finger to the dirty chinaman that can do whatever the hell they want, just steal their customers.
Last but not least, there is some big fish botters, people running 100+ accounts at once, now these guys income of gold is so great that selling at $0.5 doesn't matter, but these people are rather rare and shouldn't impact prices too much.
All in all, what I'm trying to say is, you're pretty fucked, as if with every game that you invest time to bot in, there is way more bad times than good times, but being completely honest its pretty hard to ride the storm now with duping and low gold prices going on that get lower everyday, it's basically worst case scenario without a banwave unless blizzard can turn around this stupidly insane supply from gold duplicating.