I think it depends on the ingredients rather than the price, although often products with better ingredients cost more (but this is not always the case as we have seen with some companies charging an arm and a leg for subpar ingredients). However, some of my favorite products are less than $10. Actually, many of them are...
BC'ed: 26 Dec 09
YouTube

Grand Duchess Fierce Freckles, Mistress of the Mighty Snap and Doyenne of the Potent Products Pavane in the Order of the Curly Crusaders