(14)To ensure the fairness of the price proposed to the client where his or her order is executed by the firm dealing on own account and to ensure the best possible result for the client, investment firms should consider, where available, the existing price of the financial instrument in the market or, where not available, the price of similar or comparable instruments. To avoid abuse, an investment firm should only use internal pricing models where there are no reliable data on the existing market price of the financial instrument or on that of a similar or comparable instrument.