SAN FRANCISCO—In a battle cry to consumers of trendy specialty gadgets, Sharper Image CEO Richard Thalheimer said Monday that the high-end retailer "will be undersold" by the competition. "Show us a foot massager that retails for $40 at Target and we'll sell it to you for $90—because that's how we do business," Thalheimer said. "Heck, regular stores don't even carry our virtually useless $299 ionic air purifier." In response, Hammacher Schlemmer issued a challenge to "exceed Sharper Image's price or double the item's cost."