It is too late for you to buy Bitcoin. Bitcoin prices are already too high at the moment, so buying now will cost a lot of money. Besides, at present, Bitcoin's prices are not stable, can increase or decrease at any time. So be calm and wait for the right time to buy Bitcoin
It is not too late, and the way you think is absolutely backwards. As BTC is fractional, you can just buy small parts of it, and it's highly likely that even those fractions will grow up in the future. Obviously you won't be making money hand over fist this way, but still more than what your bank would be paying you.
The more you wait, the less you make. Yes, BTC will come down at some point, but unless it happens right this moment, it probably won't even come down enough to make up for what you've lost by waiting.