Ready to meet every possible need for consumers, Costco is a wholesale warehouse specializing in low prices for items purchased in bulk. Shoppers with store memberships can pick up discounted retail items, including groceries, DVDs, books and clothing. The members can also purchase mobile phones at the store's Wireless Advocates kiosk, the largest in the area. The memberships are offered on a tier basis and arrangements can be made inside the store. This is the only Costco in Marin County.