Now it is time to sell, because Bitcoin price now is quite high, more than 8000 USD, see here http://preev.com/. 
Yes we can sell our bitcoins at this price it is profitable. after few days again it will come down that time you can buy your bitcoins. Are you sure prices will come down? Now already prices are reaching to 9000.
That's why you shouldn't sell all your investments at one price. You should book profits partially and keep some so that if prices go again high you can still make a profit. But if it goes down then you can buy some more. Both ways you can make a profit.