What ever gave you the idea you could make a profit doing that? Your just exchanging one form of currency (AD) with another (zen) to buy another form of currency (keys). (Yes yes, keys aren't actually currency, but they get used like currency so they are). The only way your going to make a profit from that is if the value…
Also you have to look at what class you are. There are a ton of rogues and wizards in the queue. When I queue up my cleric I generally get a group really fast. If you were a guardian fighter you'd probably be matched up to a group instantly. As far as I can tell the queuing system wants 1 GF, 1 DC and then any 3 of the…