Darkmoon Faire; the money playground that comes around once a month. Running from the first Sunday each month for one week, it is a great way to cash up. Luckily, you can work on it throughout the month and stock up ready for the initial few days of inflation and craziness.
This late in the expansion, the trinkets from DMF aren't as sought after as the first patch. But they do sell still! Being one of the only non-raid trinkets available they can still sell for at least 5k on most realms. If you are lucky, pick up the cards cheap from other people on the AH and resell them. I would not suggest actually crafting the cards though, as they are expensive and the resources are best put to use on shoulder enchants and other items
Fishing for profits!
Around the Darkmoon Faire are Shipwrecked Debris. These fishing nods are a great way to make some easy money. From each crate, you have a chance to get lots of different MoP materials like Ghost Iron Ore and Windwool Cloth. While it isn't the most efficient way to farm materials by any means, any level 5 can go there and fish to their heart's content. It is a great way to start up on a new server at low levels!
Another item found from fishing is the Sea Pony. This pet is only available on the Darkmoon Island and sells for about 1k gold on my server. Definitely worth looking into if you have the time and patience to fish
Rabbits and Wolves!
Introduced with MoP were two 'world boss'-type creatures on the Darkmoon Island. One being the Darkmoon Rabbit and the other being Moon-Moon. Both of these are rare spawns on the island, with Moon-Moon being more common. Also, both drop a special Companion pet which are worth a lot. The rabbit is priced around 40-60k on most realms, and I was lucky enough to grab one on the first try! Rabbit groups are generally small to minimize how many people you have to roll against, but Moon-Moon gives her loot to everyone similar to the new LFR system.
On your first visit to the island, you can pick up a Darkmoon Adventurer's guide. This enables you to pick up several different items to hand in for Darkmoon Tickets while you go PvP, dungeon or raid. One of the best parts of this is that it works year round! During the rest of the month, you can stock up on the items from your other gameplay, and sell them off on the AH
Or you can do what I do, and buy them cheap through-out the month. Typically, they drop in price after the DMF is gone, reaching their lowest prices. Now is the best time to grab them up and save them for that Darkmoon Week! Buying 10g items and flipping them for 250 is great, and these are fairly available that late in the month.
The tickets you get from handing in the items can be used to buy awesome items! These include pets, transmog items and heirlooms.
Your best bet is the pets, but don't put them on the AH straight away. Many people have the same idea during the DMF so you are best off waiting for it to cooldown and selling them. You can also buy people's cheap pets that they put up while in undercutting wars to resell!
Hopefully this helps out anyone who doesn't know how to make money during the Faire. There are lots of great ways, so make sure you make the most of all of them. Keep your Adventurer's Guide handy and stock up on all the great items!
Also, check out Dollarbills over on The Wolf of Gold Street