The so-called "cheaper" TCG pets are in demand now because they don't seem to be hit by the same duping issue/concern that the high end ones were, which makes them now rarer in comparison. They also don't appear to be available via BMAH either, unlike the kites, soul trader, etc.
Bronze Whelps, they were cheap at one point because a lot of people were doing the pre-xpac event and that's now over. Spineclaw Crabs are high because they're a pain to farm and with even fewer people farming TI that reduces the amount of crabs spawned, killed, and dropping pets.
Azaelia wrote:Only other thing I can think of is: Just because they are on the AH for that price, doesn't necessarily mean they are selling at that price
And this, too. Someone can ask 999k for a Purple Puffer but I'm pretty sure it's not going to sell.