My waterproof-ness has several levels. Have a Mountain Life hiviz jacket (from Mountain Warehouse - £20) - and a pair of winter cycle trousers from Aldi (good for showers - think they have a thin neoprene inner - were they £8?!?!). If it really tips it down I use my old motor bike trousers (about £10 and nothing gets through em). Fortunately using them in conjunction with the Aldi trousers stops any breathability issues. For my feet and hands I've spent a bit as there's nothing worse than cold and wet hands and feet. Have
Altura neoprene boots for the feet (Xmas present from the missus - so no idea on price). Have been through deep puddles and a blizzard - nothing got through. For my hands I use Sealskin Mountain Bike gloves (£20) with silk liners (£6). Again I haven't felt the cold and have been through a blizzard in them. The liners also prevent the detachement of the glove inners which is a problem a lot of people have.
I've never (touch wood) arrived at work in any state other than dry.