Staples sells many types of DPI scanners. Several other major retail stores, such as Office Depot, Best Buy and Walmart, sell various brands of DPI scanners. These scanners, both new and used, can also be bid on using online auction sites.
DPI scanners can be purchased directly from retail sites, such as Amazon. The cost of a DPI scanner depends partly on the dots per inch that the scanner can recognize. Higher DPI capacities lead to enhanced images in place of lower DPI capacities, and the higher the DPI capacity of a scanner, the higher the cost of the scanner.