I bought a bunch BTC when it was $17000, then bought a bunch when it is $14000...then the price dropped until 2 days ago. I bought a bunch again when it was 6000ish...haha, now the price went up...so, really, when is it a good time to buy? When it dropped for a while and it rose a little bit, then drop again, then buy?
I think no one doubts that bitcoin is still about to reach its peak, so even the most conservative bitcoiners predict that the price of bitcoin could reach a price of at least $100K in a few years.
If this is true, the current opportunity we have to buy bitcoins below $20K seems totally unmissable, so if you still have enough capital and you believe in the great potential of bitcoin, I think you should listen to the advice and buy more bitcoins in the current price range, if you have the opportunity.