Dont be a suit returner. Be able to say you never did that.
A man needs to own a suit, or at least a sports coat, nice slacks a couple of good ties and a nice pair of shoes. There is no telling when spur of the moment you get an invite to something and you need to look like THE MAN and you should be able to pull that off with no frantic effort.
If you have to wear a suit for the interview you will probably be wearing suits to work, at least occasionally. When I was in the suit wearing world I always had at least 6-7 suits ready to go (nice fabric suits bought on sale when good stores had sales)(no suit is better than a cheap looking suit)
Owning more than 5 suits meant each suit could rest for over a week in between wearing it. I tried to buy 2-3 new suits a year and retire the worn out ones. I did that for 15 years. It sucked.... but it paid well.
These days I hate wearing a suit, but still, I keep at least 2 suits clean and ready to go, along with shiny shoes and a pressed shirt. This has paid me very well over the years(in many ways).
With that crap said... The last interview I went to and wore a suit to the dang guy came out out wearing an untucked pressed dress shirt, no tie and slacks. it was OK, but I was over dressed. I was given wrong info on what to wear.
My advice would be call the secretary or someone and ask what people wear to interviews. Maybe even ask the person you are going to interview with. Or... maybe park or walk in to the area around luch time and watch what people are wearing.
It is always a good idea to be wearing the same uniform as the home team kind of clothes as the people who work ther, not over-dressed no under-dressed.
My best tip of all time for business? The most important person in a business in the secretary or what ever you want to call the person who answers the phone, puts your call through, tells the boss you are there. Be nice to them/him/her the very first time you talk with them. They hold the keys. They can tell you what is REALLY going on. Don't be a kiss ass or fake.... simply be friendly, kind and give them respect along with lots of presents like candy flowers money concert tickets and/or anything the desire.
Good luck, sit up straight, get a good hair cut, keep you chin up, read a bunch of web sites for the most recent interviewing tip. You can not study learn too much. Do some perusing on how to have a successful interview.... read "the best answers to interview questions" "what NOT to say in an interview" "common interview mistakes"... stuff like that.
Bottom line- nothing makes people like you more that having proper polite honest sincere confidence... when you can fake that, you have it made.