That is my opinion, yes. If you're going to wear a suit, make sure it's a well crafted one that fits you well. A suit that is poorly fitted or looks "cheap" comes off as very unprofessional - especially if you're interviewing and schmoozing for a six figure job.
At the very least, if you're on a budget, make sure you have 1 or 2 nice suits that you can rotate for recruiting, even if the rest of your daily wear suits are of lesser quality.
I don't know if it really matters for admissions interviews. Maybe someone else can chime in on that.
Another good reference point:
108-t58068?hilit=Guide+to+Recruiting+Schmoozing. As pelihu mentioned, you can often find nice suits that are discounted all the way down to the $250 pricepoint (i.e. Jos A Bank). If you want to spend a little more (say $500-700), you should be able to find a discounted Brooks Brothers or Hickey Freeman. In fact, if you're willing to drop around $700, you can probably pick up an entry-level bespoke suit from my tailor and have that be your one awesome suit. They make excellent shirts, as well.