I would sell all my Bitcoins if they get to 550$-600$.
But that's what I say every single time when I'm waiting for the right price, they I always want some more but before that the price drops. That happened this time as well

Dude if you are really planning to sell your bitcoins on that range, I suggest you should ready your coins cuz that's coming before this month ends

(just a speculation , I strongly believe on it though)
Yeah the value of bitcoins will reach at the price very soon but we want that it should go much beyond that then only we would be able to make some profits out of it, and selling all bitcoins would not serve the purpose, selling few bitcoins and saving rest for the future would be the great thing to do as we can buy some more coins in the future when prices again goes down.