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.
You should look into buying it when theres something that effects the market, like the Chinese new year that was going and the prices dropped low on that month and it raised back to 11K as we speak.