Besides this: For a lot of species, the market is so overloaded by player bred animals, that the actual market prices are already way below the price that the game suggests. For example tigers, lions and stuff like this... the game suggests that they have a value of ~ 500 - 800 CP (by the prices it recommends)... but actually you can be glad if you can sell them for 250.
I think part of that is because of the Frontier Zoo released animals. I've looked, and while the player bred animals default suggestions are usually pretty high, when you see the Source: Frontier Zoo animals on the market they're usually a LOT cheaper. I feel like that's really what is setting the market prices for some of those animals.
I do think there are some animals where there generally isn't enough of a supply (when I checked the other day there was only one page total of African Elephants, with only 1 female up for sale for 10KCC) but otherwise I think the market is fine. The only thing I'd like to see is more encouragement to not flood the market with 0 fertility animals.