I dont think aarav is being selfish. its how 17 year old boys are. they want the same thing as their friends if not better. and he sees his twin brother having much better stuff than so ofcourse he will feel insecure about and its his rights too.
agam and suhani grew up with money so they dont value money and grew up without a mother so they value her a lot more than money. aarav and nishi grew up with a love of a mother so they take it for granted and dont value as much as agam and suhani and they grew up without money to spend as they like so they value it more
maybe my views are different because i am a teenager my self. i have my selfish days too and then feel guilty afterwards