Classical guitar or any other?

I want to learn to play guitar (i've been playing a classical or flamenco guitar in music class during a year), i wanted to buy an accoustic guitar but is more expensive than a classical, and an electric guitar is more or less as expensive as an accoustic one... so what's the best kind of guitar to keep learning to play guitar... and do i can play any coldplay song in a classical guitar? i mean a friend have an electric guitar and told me that don't sound like a classical and that you can't play it like if the electric were the classical? does my friend is right?.