3. The ABC Company (Example 7.5) has identified another potential supplier for the molded plastic parts. The new supplier has bid $0.08 per part but also will impose a ship- ping and handling charge of $0.015 per unit. Additional in- ventory handling charges should amount to $0.007 per unit. Finally, purchasing costs are estimated at $25 per month for the length of the 36-month contract. a. (*) b. (**) Suppose the three-year volume is expected to rise to 1.5 million, rather than 1 million, molded plastic parts. Recalculate the total costs associated with in- sourcing. What explains the difference