I have been a customer of They Grow So Fast for about 8 years -- every since my first child was a baby. The owner is a wonderful person, who will help you find what you're looking for (she'll even notify you if the item you want is brought in for consignment). She'll also remember your name!
I have always found great deals at They Grow so Fast. I get good-quality clothing in new condition at just about 1/2 the retail cost, and it is marked down from there if it doesn't sell quickly. It's harder to find clothing for older children (they wear them out more), but I found size 130 (8-10) Hanna Anderssen sweat pants at easily half the retail price last time I visited.
All the toys for sale are fair game for the little ones, so they are kept happy while you shop (not like other, fussier shops I've visited), and by the end, you're likely to pick up a toy your child loves for $2.50!