GBC Maths

RC51

I'm sure it's been done, but I whipped this up for my own edification, to figure out how many GBCs I will need to buy in order to hit the final milestone in the solo Banquet event (I'm at around 84,000 at the moment). I did it all the way to the final milestone amount, though (117,600)

SummonerNR

What about the GBC's that you get for free from the various milestones and calendar (23 in total, pts for opening but not buying). Plus 3 of the Lesser crystals from calendar.

To be fair, I don’t know if I’ve seen a definitive sheet up here yet saying exactly how many need to be bought in order to reach the top of Solo, vs top of the Ally, milestones.

I calculated it at 37 greater ones needs to be purchased to reach Solo Milestone, and just 7 to buy if you only want top of Ally milestones. (without getting more precise by doing just 36 or 6 and then topping it off with some more of the Lesser ones).
Don’t know if mine's right or not either though.