Whilst I'm sure there's a hefty mark up, and I don't want to discourage anyone from learning to sew, I think the idea that it would be easy to recreate them yourself is a little bit ... ambitious. Simple shapes mean every mistake shows, especially if it's a delicate fabric, and it can take years to get good enough. And that's assuming you could source the fabrics easily and inexpensively. Those vibrant colours and prints won't be cheap - I'm reminded of looking round Joel and Son where £70 or £80 a metre was pretty standard.
I'd stalk them. Set up searches on every website you can think of and then hunker down and wait for the sales.