honestly, Tier 19 is good without use Premium
You need to buy Special offers with real money to get Tier 25.
I did use premium at Fxx K festival and only made to Tier 22.
TLE? I think it will be, 100% will be Special TLE Cups. Terzo and FXX K have it. and because of TLE, many player will use their Real money to get more "kit cards" so they can get TOP 100 or TOP 1%.