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 $90because 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.' 