A customer sent an order to a distributor...
A customer sent an order to a distributor for a large amount of goods totaling a great deal of money. The distributor noticed that the previous bill hadn't been paid. The collections manager left a voicemail for them saying, "We can't ship your new order until you pay for the last one."The next day the collections manager received a collect phone call,"Please cancel the order. We can't wait that long."

A doctor is complaining to a mechanic
A doctor is talking to a car mechanic, "Your fee is several times more per hour then we get paid for medical care."

"Yeah, but you see, doc, you have always the same model, it hasn't changed since Adam; but we have to keep up to date with new models coming every month."