A salesperson driving to visit a client located two hours away has a tire blow out on the highway. He walks about a mile to the next exit where he finds a service station. The owner of the station says he can replace the blown tire, but it will cost twice as much as it would to purchase a tire in the salesperson's home city. The salesperson, not wanting to be late for his appointment, agrees to pay the higher price in order to get back on the road. This case illustrates the effect of ______________________ on buying behavior.