You can buy airline miles when you start to plan for a vacation. Getting airline mile points and then using it for your travel will be a profitable one than spending your money on its expenses. You can use these points to buy your air ticket and also on your hotel booking expenses.

You must no know what profitable means.

Buying airline miles is an unbelievably horrible idea unless you are getting some sort of 100% bonus for buying miles.

For example, a round-trip domestic ticket on US Airways is 25,000-60,000 miles depending on travel dates. To buy 25,000 points would cost you $875 and 60,000 would cost you $2100 -- plus you have to pay taxes and fees for buying a ticket with miles. You can buy a domestic ticket for less than either of those fares plus get miles for the actual distance traveled for "free".

If you want to save money on tickets, buying miles is not the way to do it.

There are times when purchasing miles is more advantageous than purchasing a plane ticket.

In each and every situation, one needs to evaluate the "best" alternative.

Example: AA is currently allowing mileage purchases at a 30% bonus, and, until April 5, the cost for buying the mileage is discounted 15%.

Makes the breakeven between buying miles and buying a ticket less than a straightforward comparison.

I agree there's no one answer.

I just ponied up to buy 500 miles on Hawaiian Air because I was slightly short on FF miles for the ticket I wanted. So a $600 round-trip Seattle/Oahu I ended up paying $14.95 to buy the little bit more miles required to make the 50,000 I needed.

There's a difference between buying 500 miles to score a mileage ticket and buying 30,000 for a ticket. I should have been more clear in my first post.