In 3 weeks.

I'd suggest if you didn't collect 500 for whatever runes you need. Skip and do it next rebate.

Pill will come handy in late game. You will need it.

----

Also with charm rebate, try to get 100 boxes for rainbow. I usually did once every 2 months. I could only get roughly 50 boxes ish per month from participate all events and not buying.

Do big power jump better than small jump and missing out big prizes.