With orders of $25 or more, Amazon offers Prime members the Smith's PP1 Pocket Pal Knife Multifunction Sharpener in Glossy Exclusive Paper for $6.98 with free shipping. (Non-members can spend $49 or more to qualify for free shipping.) That's the lowest total price we could find by $4. It features a tapered diamond rod, ceramic finishing sot, and lanyard hole.

Note that this item is part of Amazon's "Add-on program" and can only be purchased with an order of $25 or more.