Pop N Lock won't honor warranty for kits sold at retailers like Amazon. From the Pop N Lock website...
Please note that Pop & Lock™ Products purchased on auction sites such as Ebay, Amazon and Craig's List, etc. will not be covered under factory warranty under any circumstances. Pop & Lock™ LLC (and Pop & Lock™ Corporation) is unable to verify whether products sold through auction sites are new, used, or refurbished, therefore, Pop & Lock LLC (and Pop & Lock™ Corporation) is unable to warranty such purchases. Pop & Lock LLC advises using extreme caution when purchasing our locks through auction sites as you'll be doing so at your own risk.
If you aren't concerned with the warranty issue then I think that is about the lowest price I have seen.