Perfect answer that buy low and sell high is the main thing people use to do with bitcoin so the same way for profit you will have to buy bitcoin at low price, according to me every time is the right time for bitcoin because now price of bitcoin is not very high but it is increasing with time so if you will buy bitcoin right now it will be saving and you will be able to sell bitcoin at most high price in market with time, buy now as it is the perfect time for it.