I never knew Anivia was worth 3150 rp

Yeah shows the same to me too https://i.gyazo.com/30470b30b622e13967b9e492aa7f8723.png

Champs drop in price as new champs are released its just slow because the release schedule is slow

630 is the BE you get from disenchanting, while 3150 is her BE cost in the store.