I was clueless about the dress expectations of the business world when I started law school. I can still remember my Corporations professor telling us one day in class that we NEEDED to buy a good pair of shoes. I didn't understand it until I started interviewing for summer jobs, then it hit home.
While you may not need several $2000 Hart Marx suits, there are a number of places to go for good quality mid-level suits. It's not much different than steel toed boots in the construction trades. You're going to be a liability to your company if you show up in front of your clients looking like you're dressed from a discount store.