The City of Ember
How we cite our quotes:
But Granny rarely went out, Lina told herself… She didn't really need a new coat, did she? Besides, how much could a few pencils cost? She could probably get a coat for Granny and some pencils. (5.11)
Oh, Lina, how quickly you learn the fine art of rationalizing irrational things. It seems like she subconsciously knows she's being kind of greedy here, but she's able to justify it to herself. Having colored pencils is surely more important than making certain her grandmother stays warm, right? (Wrong.)
It was like hunger, what she felt. It was the same as when her hand sometimes seemed to reach out by itself to grab a piece of food. It was too strong to resist. (5.43)
Lina's awareness of her greed doesn't make it any easier to resist, unfortunately. That shows just how powerful greed can be when it gets a hold of you, and how hard it can be to shake it.
Later, in her bedroom, with Poppy asleep, she took the two colored pencils from her pocket. They were not quite as beautiful as they had been. When she held them, she remembered the powerful wanting she had felt in that dusty store, and the feeling of it was mixed up with fear and shame and darkness. (5.80)
It looks like Lina has to learn about the consequences of greed from the school of hard knocks. Luckily nothing too bad happened to Poppy during that blackout. And as for whether Lina's choice to get colored pencils instead of a coat for Granny was a good one, well, Granny did fall ill and die shortly after. It could've been something she was incubating for a while, or she could've gotten sick because she was cold because her selfish granddaughter didn't buy her a new, warm coat. Just sayin'.