[header] How to know if airline miles are worth buying [title] Check how many points you need. [step] You might have some miles already saved but fall short of what you need to buy a ticket. For example, you might need 15 , 000 points to get a ticket. 
You have 10 , 000 points already, so you're 5 , 000 short. Should you buy the 5 , 000 points? [substeps] To find out, you'll want to identify how much your current miles saved will be worth.