1. create a character on Illidian - horde. in my opinion, it has the busiest AH for TCG pets. multiple copies of them are almost always there, and occassionally there is some good competition so prices drop. The rare drops from TOT are very cheap there, you can probably get Ji-rin for like 4k.
2. Farm your own realm for stuff like Fithling, Direhorn Runt (with spectral porcp) and stuff like that. Also be sure to transfer all your extra spirits and panda bears to Illidian to sell ( even if they sell their for cheaper than your own AH)
3. BMAH On your own realm, if it is low population, you can probably win TCG pets for cheaper than they sell on Illidian. Even the more minor ones are a great way to transfer gold to Illidian. I won a rocket chicken on my server for 40k, sold it on Illidian for 70k, then bought about 7 other TCG pets(all the cheap ones) along with the 4 fish and a bunch of other hard to get pets that I didn´t want to farm for. I don´t think I have ever seen a single TCG pet on my own AH, not even the ones like the grell, so getting them would be impossible otherwise.
I am at a very similar place as you, mostly I just need the big 5 TCG pets ( spec tiger, trader, dragon kite, rocket chick, tuskar kite). I have gradually been accumulating gold on Illidian mainly with pandas and spirits and the occassional Argent tourny pet from LFG-satchels.
Once you get into it, you can make a lot of gold on your main realm by buying the TOT rare drops. On Illidian, they sell for 1-3k for most of them.. on my own realm, they easily sell for 5-10k. I am not sure how much this will change in 5.4