Ethereum is on a terror these days. It's up a couple thousand percent for 2017. It's about to be traded on two more exchanges in Asia June 1. If bitcoin is too expensive for you, try buying some ethereum. It's still got a long way to go (up that is).
Think of bitcoin as a program like excel or word and ethereum as an operating system. They are different and Both have major potential!!
Finally "Ripple" is another altcoin. It's trades for about .26/coin. So it's much cheaper and it's being adopted by lots of financial institutions(it's area of speciality).