I do laugh when such question pop up, how much have you made etc, it is obvious people just want to enter the game for the money, if they are bothered about that, then they should be an early bird. The sweetness in p2e games is the long term goals, you earn gradually.

About those cards value, well that is how most games are and like you said it moves in cycle, fall and rise based on demand, moreover they sold packs not cards exactly and what you see in packs are based on luck, each players give them the value they want since they want to sell quickly