assuming you have a perfect run:

12 stamina = 24 MC
1 hour = 1 stamina

and the event last for 1 week so:
48 MC a day times 7 times a week = 336 MC

but there is a revival 2 weeks for a week so:
336MC times 2 is 772MC

if you buy all the characters in the shop once, that would be 70+300+500+150=1020 MC

thats assuming that:
1. you start at zero stamina at 0:00
2. you dont level up that restores stamina
3. you probably didnt use SC to restores stamina i accidentally use one
4. and you magically unlock the last map from the start

since, i cant clear the last map (i cant even clear the first wave) maybe im just using my MC on aria that minicost reinforcement is eye catching to me

you can probably earn more than that but i doubt that you can get all the characters without using a SC