Using miles to upgrade to premium cabins (like Delta One) can sometimes yield a higher "cent-per-mile" value, potentially making a small mileage purchase worthwhile. Gifting and Transferring
Buying miles is often a losing financial proposition because of the "valuation gap". ~3.5¢ per mile. can i buy delta miles
How to Buy, Gift, Transfer or Donate Miles | Delta Air Lines Using miles to upgrade to premium cabins (like