A company is in the process of bringing a new product to market and has incurred development costs of $35,000 to date. Further costs of $28,000 will be required to complete the development of the product. Marketing spend for the past six months was $16,000 and it is expected that expenses in this area will be $22,000 for the next six month period. In deciding whether to continue with the development and marketing of the new product, what is the relevant cost