Buying BA Avios Miles is a great option if you need to book business class flights, but there are better ways to earn miles.If you want to fly in business class, buying points might be the quickest answer. To earn the miles necessary to fly in only one direction, you'll need to pay with your credit card—and if that's not enough, British Airways also has a promotion offering bonus Avios for every six months of card membership. Earning points and miles through ordinary purchases, credit card welcome bonuses and travel is far superior.