Normal cost for iruka fragment is 30 cp/frag.

But, you can get max 20% discount here. So, each frag will cost 24 coupon/ingot that way. and you can buy max 80 frag during this whole event period.

I have a question: is there a limit to how many mysterious scrolls you can get per day?

I want to get those 5 seals for sure, as well as a few other things. If there is no daily limit, then will pop a few stamina pot on monday, for a few extra exp as well.

Does anyone have any confirmation on this?

'Clearing plot/elite instance gives you mysterious scrolls'- does completing them manually count?
Or, do you have to sweep them to get mysterious scrolls and sage key?