When I buy for business I always buy the best thing I can afford, in a classic cut. I don't like things that will date - I want to wear that black blazer and skirt for as long as I can wring value out of them. They themselves make a statement, and then the oomph comes in the details, like edgy jewelry, bags, and shoes.
For example, if I were a money-raking attorney like my sister, I would have bought three Jil Sander (or similar) suits and worn the hell out of them with beautiful shirts etc. She, instead, elected to do the very opposite and bought as many things as possible, as cheaply as possible. And they did look cheap. This to me is false economy, but, whatever.
I know you're an admin right now, but general advice is to dress for the job you want, not the one you have. Or rather, the job you want at that organization (if your dream is to be a circus clown or burlesque dancer, I might keep that out of a business workplace). IMO you always look well-presented, btw, so that's not to say you're NOT doing this, but keeping this approach in mind works well.
Were I you, I'd look for Theory, Narciso Rodrigues, and other high-end suits and separates, possibly used. (http://www.ebay.com/itm/310342.....1438.l2649 for example). Then you can add something a little edgier, and easily swappable when it dates - such as shirts, shoes, etc. But I always say start with a very classic, high-end foundation, and you really can't go wrong.
