Best plat return ratio actually. 25 plat a run and each piece sells for 200k. I run at 16 with Arcane hooks, fast killing of the boss. That said, I have more fun farming mauso even if it's less gold, and once set up, practically free to run everyday.

If you're going to blow plat then ruins. If you're doing it free, might as well run mauso. That's my formula happy farming!