It's getting too late for the average person to invest & buy 1 whole bitcoin even now. It's not too late to invest though, buy what you can afford, even 0.1 bitcoin may be worth lots in the future.
I don't think it's too late for the average person in a 1st world country to buy a whole Bitcoin.
Even 5000 dollars is very little for an investment and that's pretty affordable for anyone who makes more than 1200 dollars per month.
It is never late to get started, the price if bitcoin is rising and in coming day it will rise more so that one should invest now to get benefits in upcoming days and can easily get profit on daily basis, bitcoin is now 5000$ and in coming future it will rise again and it is a very reasonable investment to get started and one day this will go to the higher index and give benefit to you.