So line items may very well be the highest way to buy for price, depending on the item and the quantity. Service is best on prime vendor. One, the prime vendor is bringing out full trucks, so trucks and drivers are dedicated. You'll be the first and only stop. Also, the prime vendor is assured of how often he is going to be on your campus so he can plan his business.
Service is better with limited, and it is good in the other categories.
A line item bid for only 40 cases could be the first stop or it could be 12th stop. You can ask for the most in a prime vendor relationship. There is an assured contract with an assured cash stream that allows a distributor to provide more in the way of value-added services. On limited prime, you can get almost as much. On a line item bid, you have to pay for value-added services.