With all the good news coming out in favor of bitcoin like
Expedia accepting bitcoin etc it's time to buy with the price going down. You will not be so lucky next week. I strongly believe it's going to reach $700 by end of next week!
Honestly the best time to buy is when the value of crypto coins will dropping low which you have a big chances to earns much many coins as you can.And wait for the right time that the market goes up and sell it automatically.