Overstock.com offers the Astro Pneumatic Tool Worn/Damaged Hex Bolt Extractor T-Handle Set for $19.99 plus $2.95 for shipping. That's the lowest total price we could find by $26. It features a rotating tip design for grabbing worn or damaged hex bolt surfaces for extraction. The set includes sizes 4, 5, 6, 8, & 10mm.
Update: Click this link to cut the price to $17.99.