A shopping trip to Klang, Selangor costs RM 500, while a similar shopping trip in Kuala Lumpur would cost RM 600. The shopping trip to Klang, however, involves transport cost of RM 50 and travel time (valued at RM 50). Considering the economic costs of shopping, which option is better, i.e., shopping in Kuala Lumpur or shopping at Klang, Selangor?