For as long as fiat money exists, it's always a good idea to dump it in favor of BTC. I don't know if it's gonna be for 5 or 20 more years. Better be early than late. Until that time, we will see many temporary ups and downs, but they are meaningless. I will buy today. And again next month. And the next month, and the next... Regardless of price.

Then again, if you want to be more precise, I like rat03gopoh's suggestion.