Personally speaking, I'd tell you to not invest too much into a gacha game. Even if PM is a bit more generous than normal gacha games.
You can go F2P or invest a minimum amount of cash to make yourself a Fish or a Dolphin, but at the end of the day, it's still a gacha game.
The game is fun mind you. Really fun. I would recommend trying to stick to the F2P route instead of trying to get any IDs if you try it out.
Since the game is balanced around base IDs with its content. And grinding as a F2P player isn't too bad either.
There are other factors than the pure *potential bad future* and two of them are inherent to Gatcha by its very nature.
First factor is that I don't tend to like too much randomness... or, more precisely, I do not like randomness I cannot manipulate inherently in the game system or outside because I get very interested in some particular strategy and want to try it (without having to pay).
For example, let's see... I am currently playing a tabletop named Kingdom death: Monster intensively, you control survivors that can have philosophies that decides a number of things they can do in it.
I have no problems with the fact that you can't have all the philosophies in a game normally (you get only part of them each campaign) but it doesn't change the fact that I am going to simply choose the tier 3 (the *bests* you get, but you only obtain one of two) myself instead of drawing it randomly because I took a peek at what the two were and fell in love with this one while feeling *meh* at the other.
My favorite collectible card game is also VTES for the simple reason that due to the game being out of print, players are very accepting of proxies (cards you printed yourself), meaning if I want to try a stupid deck I made myself, I can simply print it. (And I make my deck lists to manipulate the odds of having the correct cards in hand, by the way).
I can't do that in a gatcha, if I want to try a special stupid strategy, I have to hope I pull the correct character, and probably won't because those are made to prey on this kind of behavior.
The second factor it simple time:
I don't have time to watch a thing that long, the way my attention works means that I will either do only that or not at all, and if I want to play a game that will last 400 hours, I want to be finished after it.
But I think we talked enough about all this, and this is getting off topic.