I have built up a good collections of jackets over the years that have been lifesavers at times as you can mix and match them with skirts, trousers and dresses. Have you tried good old TK Maxx? They do some super-smart jackets, trousers etc. At the moment larger Sainsburys have some really expensive looking things in for a fraction of what you would pay in Next or Priciples.

Congrats on your new job by the way - good luck with your career!