Everyone loves small pets. Especially rare ones. Soon, the Trial of the Champion pets are going to be VERY rare. This is because it takes a LONG time to even farm up the seals to get one. At the moment they are 1000g each normally.
What you need to do is buy up a couple of different ones of the OPPOSITE factions. Then store them until the expansion. People are going to eventually stop farming them and they will become very rare. Especially at 85 and even as soon as patch 3.3 people may stop farming them.
These are the ones you should be looking for.
If you are Horde:
Teldrassil Sproutling - Item - World of Warcraft
Dun Morogh Cub - Item - World of Warcraft
Elwynn Lamb - Item - World of Warcraft
Mechanopeep - Item - World of Warcraft
Ammen Vale Lashling - Item - World of Warcraft
If you are Alliance:
Tirisfal Batling - Item - World of Warcraft
Durotar Scorpion - Item - World of Warcraft
Mulgore Hatchling - Item - World of Warcraft
Sen'jin Fetish - Item - World of Warcraft
Enchanted Broom - Item - World of Warcraft
TLDR; Buy opposite faction Trial of the Champion pets and save them until Cataclysm or patch 3.3.