Baby clothes are expensive! To add insult to injury, they never even wear some clothes because they grow so quickly. If you don’t have hand-me-downs or a network of moms willing to pass on stuff, we have had great success at op shops (or thrift stores as you call them in America).
Most baby clothes aren’t worn very much, so they’re in much better shape than adult clothes… and the shops near us have enough of a variety that it’s pretty easy to find something that fits. A quick wash when I get home and they’re as good as new.
I know that you aren’t able to get the latest styles, but your kids can still look really cute… and it doesn’t hurt to teach them from a young age that material things aren’t always what they’re cracked up to be.