Dermalogica products are mainly sold in beauty salons so have a look in your local Yellow Pages and see if any salons near you stock this brand. You can buy Dermalogica products at lookfantastic.com at reasonable prices.
depending on where in essex you live - but in Brentwood there is a college that trains beauty therapists and they sell the dermalogica products and there are also a few salons in Leigh on Sea area that use those products so you can buy them there. hope that helps