I've been keeping track of spending on clothes since the start of the year and it's £760 so about £85 per month. That's just clothes not hair and beauty, although I don't spend loads on hair or beauty probably about £20 a month.
I'm mid 30s and work in a professional environment so need to look smart but don't need to look overly formal (no suits needed).
I buy higher end high street so Reiss, Whistles, Hobbs, Baukjen etc. However I only buy in sales or via eBay. I'm also a massive TK Maxx fan.
Examples of things I have picked up this year are:
two Baukjen dresses each for under £30 for work from the sale section of the website
Boden skirt around £10 - from the sale section plus I had a £10 voucher
Brand new but without tags Whistles dress for about £25 off eBay
Gorgeous leather jacket £150 from TKMaxx.
Reiss dress £30 at the very very end of the sale
I've also been a guest at two weddings and got dresses for each from TK Maxx - one was a Chloe dress for £60 the other dress was £30 (can't recall the brand but it received loads of compliments)
So my money stretches quite a long way and I buy quality.