All good outdoor kit and gear is expensive and cycling is no exception. I try to support our local bike shops but I do recommend taking advantage of the bargains that Aldi offers periodically. Thursday 27th September is cycling offer day – see http://www.aldi.co.uk/uk/html/offers/offers_week39Thursday12.htm for more info.
My advice is be selective as you generally get what you pay for. Not all the cycling stuff on offer is value for money but some of what is on offer this week is good value – so much so that it will nearly all of it be sold in a remarkably short period of time.