If you have all gaurds you have around 65 time you base SED.
So if you have 2M base sed you can have 130 M event SED.

I got 40M EP with just 8M event SED and I have used 10-20 pudding and just 2 e-gacha in this event.

Big spendes that are very active can easyly get 1-2 B EP.

There are really no reward for getting 1B EP so why spend 500$ .

Free players can get almost same reward as players who spend 1000s of $.