: If you are short by a few thousand miles for a specific, high-value redemption, buying a small amount to bridge the gap is often worth the premium.

: It is almost never worth buying miles for coach/economy seats, as the cash fare is typically lower than the cost of the miles needed.

: Buying miles can be significantly cheaper than paying the full cash price for international Business or First Class tickets.

: Only buy miles when airlines offer significant bonuses (e.g., 60%–150% more miles) or discounts.

To determine if a purchase is worth it, calculate the : 4 Times It Makes Sense to Buy Airline Miles - NerdWallet

: If your existing balance is about to expire, buying the minimum amount of miles can reset the clock and save your entire stash. When to Avoid Buying