TL;DR: ran the numbers from May 1st to June 1st and grinded ~11,578 units from the game F2P. i hope these numbers are right but if they're not, correct me.

-grinded ALL milestones from the 4*, 6* basic, and 6* feature
-grinded for 2 6* featured champs
-when a featured grind wasn't on, got top 1-5% in the both the featured and basic 6* arenas
-when a featured grind was on, used boosts in the 4* summoner trials arena and stopped at 4m in the 6* basic
-missed a few days from the catalyst arenas and the 22hr solo events
-100% all difficulties of EQ. i didn't track the exact number but i assume it's still 600 units like it always was
-gained 2.27 million battlechips for an average 4266 units (1875 units/million)
-there's around 887 units that i can't account for, they might come from alliance events like this and other areas, i'm not really sure:


...if you want to spend $15 and get the sigil (75 units a week) and the $5 unit deal (735 units a month), you can get 12,613 units.
i don't advise this. it takes a large roster, it's hard on the fingers, it's not practical, sustainable, and worth the effort. don't ask which torture camp i was stationed in but luckily they had good wifi and my captors let me out for an hour a day to get some sun. thanks for reading!