I like to follow the fashion trend since i was studying fashion design n been involved in this line.
Why children's branded stuff more pricey is b'coz the fabric quality (non irritable to baby's skin, non allergenic), good styling (good fitting, comfy, functional and easy to wear), and safety standard (this include accessories like button won't get pulled off easily, zipper with no rough/sharp edges, no long strings for babywear).
I've ever involved in sample development for baby Gap and I can tell you they ask for alot of requirement starting from fabric untill finished garment.. a single mistake is intolerable coz it might harm someone's baby... This type of quality control that involved alot of people, thourough checkings, and costly tests, makes this brand trusted by all mothers.
But ofcoz wether or not you want to dress babies with branded stuff are all depends on our budget. I didn't buy all branded stuff for babies just for the sake "so ppl would know I can afford it" thou, coz I always dressed my girl with light clothes that mostly not much accessories on it hehe..But mother's should have the knowledge too which fabric is good for our babies and which style is safe and suitable for babies, that's it...
For me I would say mix and match is best ... dont't overdo your baby coz they grow very fast, but you still can dressed them properly and presentable thou.