I get lots of my clothes from Ebay - lots of nice vgc suits! Got an armani trouser suit for about £15.
Only trouble is you don't always get quite what you want. I bought a suit described as brown tweed, and looked it in the pic, but turned out to be a horrible yellowy-mustard colour, and another had the labels all removed and I swear the jacket was 2 sizes bigger than advertised! (Good job I don't really care what I look like at work)