A way to save BE on new Champs
Riot removed the champion mystery shards but replaced it with a complete mystery champion. Before it was 1700x3=5100 ip to buy and reroll for a new random champ, but now its 3950 BE for a COMPLETE Hextech mystery champion.
If you get all the cheaper champs normally (450, 1350, 3150), then you would save a lot. This means you save 6300-3950= 2350 BE and 4800-3950=850 BE. You will save a lot in the long run. I had 7 remaining 6300 champs yesterday and i bought them all with only 27650 BE. I also bought some extra mystery champs for the future, so when a new champ comes out at 7800 BE, i will save 7800-3950= 3850 (almost half price).
Edit: It actually says the champ unlocked is guranteed to be worth above 790 RP = 3150 BE, so you only need to buy all the 3150 champs before unlocking the mystery champion.