How many diamonds do you think we can stack for the Arc costumes rerun at the end of the year?

How many diamonds do you think we’ll be able to stack by then? I’ve got 60,000 right now, but I’m not sure if summoning on day 1 for Volo will still leave me with enough to pity all three Arc outfits in December. Should I just stick to the 100-diamond dailies and wait until the last day to summon, just in case? I kinda want to summon on day 1 though… do you think I can afford it?