I bought It I bought it a free few weeks ago and I would do it again, no doubt. But for me as you said there were other priorities: I bought my set full, I also bought the charm expansion, and then this.
What I like is that most days one of the 3 slots give me some creatures I can hunt.
It is Up to anyone, up to anyone. I would not buy It as soon as posible possible but yes when you have extra money to spend.