Bitcoin is and always will be very volatile, but this does not mean having to give up his purchase. If you look at the chart of growth rates you will see that every year the price of bitcoin is increasing. This trend will persist for a very long time so you can buy it at any time.
so i should buy bitcoin at this point or when the value reduce.
Yes, it is still you need to buy more as long as you can afford to do it. Because like what others community expecting about in bitcoin it will reach 10, 000$ or more and more. Don't wait for the time when bitcoin reach it. it maybe down for its for awhile only then it will resume to the original value or more.