I just finished my interview with a MAJOR national airline for sponsorship in Europe. I have been successful. Anyway, while I was there, no one wore a suit, not the management or even the hopefuls. The hopefuls all wore long sleeved shirts with a tie and yes shiny shoes. Please no loafers (you'd be surprised...). I was made to sit a few metres from the interviewers so they could see me from top to toe. This is standard at most airline interviews. Please please please dun figid. You will automatically lose the interview if you figid. It is THE thing that interviewers look for. I cannot stress this enough. You definately dun need $400. In fact any K-Mart shirt will do. So as long as it is NEW and PRESSED. It must must must be NEW. Wear a QUIET tie with small red patches/spots, though don't overdo it with the patches and spots.
FYI, the interviewers wore shirts. Some long sleeved some short. 90% of them did not wear a tie, which is the way I think it should be. Maintain an image of professionalism by not overdressing. Conducting an interview with a full 3 piece suit is overkill.