Hi, it depends on the size, condition, place, numbers of plants - shrubs, trees and how long is no one cared. If you live in West London, Windsor, Slough - I can give you the quote, but I have to have a look it before.
There are many different options when landscaping a garden. The first thing to do is to try and decide what sections of your garden are going to be used for what purposes. Paving, decking, turfing, planting, barking all work out at different rough prices per square meter so of course size plays a large part as well. The best thing to do is to get at least three different quotes from reputable landscapers.