High-quality cell phone covers are available on eBay. In the Search box, type "high-quality cell phone covers" to view a selection. Check the boxes on the left to narrow the search by phone type or cover attributes. Typically covers are available in a variety of quality levels and price range.
Many retailers other than eBay sell high-quality new and used cell phone covers. There are large assortments of covers on websites such as Amazon, Best Buy and Overstock.com. Reiko Wireless Accessories has wholesale cell phone covers. Covers at are also available at brick and mortar stores such as Best Buy.