Once in a while, a great opportunity comes along to acquire more BTC. They don't last long. We are in that moment now, with prices nearly 75% off the peak.
How can you be sure that this is the best time for shopping ?! The price of Bitcoin can drop a lot more. I would not be surprised if I woke up tomorrow and saw $3,000 ... and I still would not be sure if it was the best time to go shopping.
Anyway i'm sure that this drops have to stop soon, and next months trend will turn up.