The devs are great but that's no reason to ask and ask and ask and keep asking over and over again, you know?
This system works fine. There is literally no reason to complain, and yet you are saying this is unfair? Sure, they sell 2 extra slots for 1500... But you have THREE SLOTS that you can use for free when you start the game! People will always find a reason to complain, won't they? No matter what, people will complain.
It kinda irks me a bit that you are complaining for this. This system seems fine. The devs are fine. Everything is fine.