Nutrend via Newegg offers the Autel MaxiScan CAN OBD-II Scan Tool, model no. MS300, for $12.99 with free shipping. That's tied with last month's mention and the lowest total price we could find by $2, outside of the mentions below. This device retrieves generic and manufacturer-specific Diagnostic Trouble Codes (DTC) and retrieves VIN (Vehicle Identification Number) on 2002 and newer vehicles that support Mode 9.
Two close prices: Invictus.icc via eBay has it for $13.99 with free shipping; International Trade Centre via eBay has it for $14.09 with free shipping.