Westcoastgirl, I put off my suit and other professional clothes shopping until after I received campus interview invitations because I thought I might jinx myself otherwise.
Generally this is a bad idea though. Sometimes you have a very short turnaround time between invite and the interview and you have a boatload of other prep you need to be doing, not scouring stores to find a suit that fits right. It worked out for you, but in general, I would recommend that most people keep an eye on sales at stores that fit them well and buy a suit when they go on sale. For me, that is Ann Taylor and I have nice pieces from the same suiting line that I can mix and match and that were bought on sale. If I waited until the last minute, I probably would have spent an obscene amount of money like you did.