2x dorans is not standard. I would say I see 80% at least with 0-1 Doran's. Your example build has absolutely no mana or mana regen, meaning you're either dumping huge amounts of gold into mana potions, or you aren't farming nearly as much as you think you are, because it's not mathematically possible without sacrificing absolutely all lane pressure.
The idea that you can have one standard template of items for all AP champs in the entire game is so ludicrous I'm not even gonna touch that one.
...
That's the thing, the Dorans ARE the regen. 2 should be more than enough to sustain your mana to have presence and farm easily early game. And then there is this wonderful thing called Blue buff that regens your mana incredibly fast and takes care of mid game and late game regen easily.
@ the whole standard template thing, I phrased my statement wrong. I completely agree with you when it comes to every champ and every game requiring different itemization. I was just trying to imply that there is a set of core items where in a perfect game, a general AP champ like Brand would most likely pick them up. Obviously no game is perfect, so maybe buying a QSS would be needed against something like a Skarner.
That seems like a big waste of 1700 considering doran's is supposed to be used as a "i'm stuck in a ditch better buy a temporary item that has good stats but goes no where to get back into the game", or used as an early advantage. (aka first item)
First of all, 2x dorans are only 950 gold. ~1700 gold included the tier 2 boots and wards.
I really don't think you understand just how cost efficient Dorans are. They are incredibly cheap and will last you well into mid game and help you dominate your lane because of the AP, mana regen, and HP. They aren't just for getting back into the game. If your laning opponent were to buy a Blasting Wand (40 AP) to your 2x Doran's (30 AP, 200 HP, 10 MP5), you should be able to dominate him easily.
Blasting Wand costs 860g, 2x Dorans cost 950g. 90g difference for so much more useful stats. You're probably going to say "but doran's don't build into stuff! Blasting actually builds into stuff!" which is true, but any competent player would be able to outlane you so hard if you came back with just a blasting wand, keeping you from getting those higher items, while he free farms.