I am a free player and newer spend any money on PeroPero. I just got 530K SED without slayer bonus and I only need 50 SR-level and 500 R-Level to max all my girls.
I been at 1-3 untill yesteday. I got the 13th higest SED I think and most if not all the players with highter SED are P2W players.
1) Staying at 1-3 make you SEd grow fast
2) Staying at 1-3 dont Reduce total SED untill all your girls are maxed...
Faster way to get good SED without spending money are staying at 1-3.
When you got level 50 and unlock 5 extra level staying at area 1-3 is not worthwhile any more.

I would suggest leave area 1-3 when you get clostr to level 50 or when you are very clost to have all you girls at max level...

If you dont want to spend lot of time on spins go to area 5-3 spins cost 5 energy but you can have 2 quest at same time.