I have a Unranked Acc with all Champs that was Master last Season
Maybe you can just play it down
has 90 Skins and 8 Rune Pages.
Also have a Silver III with around 30 Champs missing. Was gold last Season and has 40 Skins.
Selling the Unranked Master for ~60€
And the Silver for 30€.
My Skype is samuraisanrl