Believe it or not, you can still make some gold off the Darkmoon Faire Card: Greatness.
While grinding out the Insane title Feat of Strength for a second time, I was pleased to see that you can turn in the cards for rep and still be able to sell the card (instead of DE’ing)
I was able to purchase and craft the decks during non faire times for around 3k and over the last 2 months I sold 8 decks for 4k+ each.
The other decks (besides the Illusion card) have also been profitable for me to purchase a deck and turn it into the actual trinket.
Check your servers prices and you may be able to tap into this quick easy way to make gold.