I always go to Bear's End when I need presents for my nieces and nephews because they have the most AMAZING range of kids toys/clothes/hats/cute shoes and stuff you'll find anywhere. Just going into the shop itself is a real experience. It's so full of stuff you can barely move. The woman who owns it is very funny though she does need to tidy up the shop a bit.
Approximate cost: $Not cheap but great quality stuff
This store has a lovely variety of children's clothing ranging from newborn to primary aged children. You can always find what you are looking for and much of it is usually on sale.