In the last weeks I made 24 Darkmoon Cards of the North. That did cost me around 4k gold in herbs (Adder's Tongue, Icethorn, Lichbloom, don't use the cheaper Northrend herbs, because they only give half the Snowfall Ink). From those 24 Darkmoon cards, 7 were "of Nobles", which is 1 more than the statistical average, lucky me. 6 of these nobles cards I sold for 1.5k gold each, making me 9k gold, for a nice 5k of profit. I'm still sitting on the last card, because the market crashed, and there are several cards for 750 gold on offer, half the previous price.
Which means that if I spent another 4k gold on herbs, milled another 100 stacks, and this time would get the statistical average of 6 nobles cards, I'd barely break even at the current price. And if I'm a bit unlucky with the number of nobles cards I get, or the price falls further, I'd spend a lot of clicks and lose money in the end.
Well, a market in which you can make 5k profit in a few days without leaving the city was bound to crash. But you might have noticed that I didn't talk about 17 other cards that weren't "of Nobles". I sold most of them too, but for prices as low as 20 gold. I had lots of chaos cards, so I bought a missing card cheap, made a complete chaos deck, and then tried selling that one. After continuously lowering the price for it every day until I could find a buyer, I ended up getting a lousy 250 gold for it. The people who bought my nobles cards for 1.5k needed 8 cards, or 12k gold for the nobles deck. So why is a chaos deck worth 250 gold, and a nobles deck 12,000? Because the nobles deck gives the best trinket in the game, giving you +90 of your favorite stat on equip, plus a chance of an additional +300 when you either deal damage or heal. The chaos deck on the other hand gives a rather useless trinket, which does nothing on equip, and just a minor bonus to crit and resilience when it procs. The undeath and prisms deck give somewhat better trinkets, but by far not as good as the nobles one.
I wonder why Blizzard designed these to be so unbalanced. Previous darkmoon cards were closer together in value. Of course it would be hard, if not impossible, to design the decks so evenly balanced that the cards would all be worth the same all the time. But the huge difference between the chaos and the nobles trinket is somewhat surprising. Well, if you happen to need a level 80 trinket and the chaos, prism, or undeath one are good enough for you, you might want to pick one up now. Every inscriber is apparently trying to make nobles cards, and in the process the other cards have become dirt cheap. Even the nobles trinket dropped from 12k to 6k. Me, I'm out of that market. I made my money and moved on before the market crashed.