User blog comment:QuantumFeint/PBE ADC itemization/@comment-15244341-20140609210804

Long story short. Essence Reaver gives: AD, CDR, LS and mana sustain. These stats are all in ONE 2800~ g item. This is really good for so many reasons... You don't delay TF as much as with BT since the final item is cheaper and the overall item gives a lot of things that were hard if not counterproductive to get. See, Ezreal getting a Tear to build Manamune for the mana regen, which pretty much meant 700g spent on nothing of value bottom lane for the whole laning fase. Not to mention none of the components cost 1600g, which means you might have to artificially extend your time in lane to squeeze the last hundred gold to get something out of your back.

Is ER the new BT? No, that's not its purpose. Is it a good buy? I'm going to say yes, on the right champions, which is perfectly fine for an item. Also, Riot has no problems changing numbers if needed.

And, BTW, Losing HP on a squishy champion for 80~ mana is a TERRIBLE deal. Not to mention the components cost as much as Bloodthirster's do (2400) while giving 30 AD and 24% LS. This is beyond terrible for any ADC such as Ezreal, Lucian or Corki which are notoriously squishy champions.