Amazon discounts a selection of LEGO Friends sets, with prices starting at $3.19. Even better, most qualify for buy one, get one at 40% off. (Discount applies at checkout.) Plus, Prime members net free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping starts around $5.)
Note that Target is matching many of these prices, but doesn't have a BOGO 40% off promotion.