I've worn a suit to every job interview. Only twice have there been any comments about it.
In my early 20s before I became more clothes-conscious I wore a JCPenney special and the SE at one of the nation's biggest papers made a snooty comment about it. It was, in fact, a cheap suit and looked like a cheap suit. In my late 20s I unwittingly went completely the other way. This was in 1988 and Neiman-Marcus was having a heck of a sale and I paid $350 for a very nice, conservative navy suit that the salesman assured me was an incredible deal. A woman I was seeing at the time called it "an IBM executive suit," and I'm still not sure if that was a compliment or not. I no longer have the suit because like an idiot I put a conspicuous hole in the jacket one day while smoking and drinking, so I threw it out. But for some reason I saved the nice wooden hanger that came with it, and now that I know more about clothes I could just about shoot myself every time I see that hanger in my closet. The hanger says "Oxxford Clothiers." Oxxford makes its suits largely by hand in Chicago, and today you'd pay about $3,000 for that suit. GWB wears Oxxford suits.
The current job interview suit was bought used at a consignment shop for $300 about 10 years ago and is probably the equal of the Oxxford. Someone had it custom made, but it fit like it was custom made for me. I showed up at a job interview and the SE said, "You are not allowed to dress better than me." But he hired me anyway.