Magic Flask (basic item, like giant belt, but for mana)
cost: 925g
475 Mana.

Magic Flask + Fiendish Codex = Sorcerer's Scroll
cost: 925 + 1245 + 630 = 2800


550 Mana, 35 AP, 10 mana/5
Unique Passive: 20% CDR

Why would someone want this? It might be a little useful on Singed and Ryze, but who else? Blitzcrank maybe?...

with the low ap it only seems like a specialized item for a few select champs like ryze singed and blitz, no one else would use it as they care more about ap than mana