Funnily when I read the jap wiki, most of stage 15 and above maps have power requirement below 470k (yes even stage 33. Reaching 400k doesn't take too long time (especially considering DMM generousity) and it's easy to find any helper with minimum 100k power.

I'm on stage 16, bearing with RNGfuckery right now. Let's see if I can reach stage 25 soon.