Division X makes a part that it sells to customers outside of the company. Data concerning this part appear below:

Selling price to outside customers $69

Variable cost per unit $10

Total fixed costs $20,000

Capacity in units 35,000

Division Y of the same company would like to use the part manufactured by Division X in one of its products. Division Y currently purchases a similar part made by an outside company for $60 per unit and would substitute the part made by Division X. Division Y requires 2,000 units of the part each period. Division X can already sell all of the units it can produce on the outside market. What should be the lowest acceptable transfer price from the perspective of Division X?