I've been doing a lot from Atom Retro recently, but I think that's more a tribute to the shop's versatility and consistency in producing sharp stuff than my own choice.
Anyway they've got some pretty snazzy suits (I recently bought a black one) like the one opposite for just under £200. Which, considering the quality (particularly fine) is an absolute steal.
This one's quite neat - with a contrasting collar.
Full ad here.