Or you can ignore short term bubbles and crashes and invest long term, maybe for a couple 2/3 of years.
Agree with post above, it's all up to you and how much you can lose! good luck :-)
I usually invest when BTC crashes and gets down to $500.
Yes, that is the correct way. 500 would change, though, I think we are already past that, so the only question that you need to answer to profit from BTC speculation - is when the "crash" is over.
You can't really predict the bottom (Unless you used the empirical rule: bottom is 2*previous_ATH)
But I agree with you, maybe $6-700 was an easy entry point