Right now, threadUp (an online consignment store for kids) is offering a FREE $10 credit when you use the code SAVE10 at checkout.
Shipping will run you $6.95 or it is FREE with $40 purchase.
Or you can use code SHIPJAN13 at checkout and get your shipping for FREE.
threadUp prices are a little more than garage sale and a little less than consignment, but they had a lot of brand names. You should be able to pick up two pairs of jeans for the price of shipping.