I used to shop at Payless Shoe Source for kids shoes. When the kids are growing so that every summer you need to buy 3 pair of new sandals, it's important to look for a good deal. However, it seems the shoes from Payless Shoe source are pretty cheaply made. They are stiff and because they are not usually made from natural materials, they don't really soften up and become comfortable.
I think if you are looking for inexpensive summer flip flops, or slippers, Payless Shoe Source would be fine, but if you want your feet to be comfortable, invest a little more in your footwear.