Looking for value advice

Before I lost my old log-in streak (989 days) I had enough of each cat to make mega. (That was and still is my biggest dream and goal)

ofcourse this was years ago so now there are more cat sorts.

I am mainly wondering how easy/hard it would be to collect all the cats normal/neon or mega version. What would people trade for them?

I am not looking for the other cat sorts like mecha meow, glormy leo, ocelot etc. Only the pets that have the word "Cat" in their name