The reason to but Bitcoin now is beause acceptance of Bitcoin is increasing day by day along with its value. You will see tremendous growth within a span of 1 to 2 years.
buy now since we can still afford to buy for few next months bitcoin will be so much expensive to buy.
I would say anytime you can buy, the supply is limited yet the demand is increasing, there is nothing to worry about the price
as eventually it will rise, save for long term so you will not panic.