Even at a price of $ 1000 is not worth selling Bitcoin. Price will rise until the total popularization of Bitcoin. Also, when they are already extracted all the coins (around 21M), the price can only grow - it is the law of the free market, ie demand and supply. When mining of Bitcoin will be finished - the supply will completely stop, and the demand will still be growing. It will make the price will have to rise. So hold your coins guys!
With that logic at hand, you'll be forever stuck in a loop. When the price reaches, 1000$, 2000$, 4000$, 8000$, or no matter what the price is, you'll have that very same thought in your mind. You'll think that it's not worth selling since it will reach a much more higher price in the future. Well, that is true. If you imagine it, the potential of bitcoin having a price increase is almost infinite so you would probably end up not selling your bitcoins ever.