My estimate is BTC will hit 450-550$ in 2016 ( this year ) later i think over the next 4 years its will hit 1000 - 1500$ for each BTC but its hard to say, but we need to dream ^^ and now when Steam soon allow BTC payment, i think the BTC will hit new price levels again (more than previous record).
Are you serious, we will be way higher than that this year, and let alone in 4 years. It doesn't take much money coming in to make the price go a lot higher, The marketcap is tiny so any rich investor coming in is going to double the price easily. Once Steam kicks in it's going to be fun seeing the price go to the moon.