First of all it is not illegal to sell or buy miles. It may be not allowed in the policy but you are not breaking any laws. A recent lawsuit brought by Delta torwads a mileage broker in New Jersey was thrown out of court becuase the court claimed there was no merit. You will always run the risk of Delta finding out but if you know what you are doing you will have no problems.

A better idea would be to tank up your miles with a cheap mileage run to get the mileage account up to a level that you can use.