If you're a somewhat standard size, you can find great deals on suits at places like TJ Maxx and Nordstrom Rack...
I'm a bit older than you, and for the dressy part of my job (maybe half?), I have 3 suits I like, plus a few blazers. Blazer plus black trousers or plain pencil skirt plays dressy but not looking like I'm going to a job interview. My recent blazers have come from LL Bean, believe it or not!