I bought a Regatta waterproof jacket from Otterburn Mills in 2008 (forget the price, wasn`t much). I treat it every now and then with a waterproofing spray, £1.49 from Lidl. Does the business, keeps the water out, and when the weather gets colder I can zip in my Regatta fleece - so I stay dry and warm in really bad weather. The fleece, btw cost £10.00 in 2008.
Incidently, talking of Lidl - apologies for going off topic, but I`ve just bought a perfectly servicable waterproof jacket from Lidl, for - wait for it ... £14.99. Don`t really need it `cos I still have my Regatta waterproof from 2008, but I couldn`t resist at that price!