I think you should edit and correct your figures; $30 is different from $30,000. 
 
One thing is to have a target; another is to hold onto your decision. If you eventually meet your dream target and, out of greed to make more profit, you miss the chance to sell at that price,
To me, it's advisable for you to hold your coin and never sell low, because selling at a lower price when you have already seen a higher price might make you look like a fool. At some point, it's good to sell below your target if you see that the market is dropping. In order to stop losing money, you can sell below your target. 
But it's always good for you to hold onto your target very strongly; don't allow greed to control you.