Great price for 5KG decent whey isolate, in my opinion.
To get it for £49.39 (usually £74.99) you must use the price beater (http://www.myprotein.com/uk/pages/price_matcher). In the URL box, type www.discount-supplements.co.uk, click 'check', and then locate the Impact Whey Isolate 5kg. For some reason, it only works for the Smooth Chocolate flavour, not the Strawberry Cream.
Spend an extra £10 or so to get the total up to £60, and you can also save 15% using the code 'SAVE1' (or 20% using 'SAVE2' for orders over £100) and get free super saver delivery. I bought some Instant Oats (again, using the price beater and www.bulkpowders.co.uk) and multi-vitamins...
UPDATE: DISCOUNT CODES EXPIRED A COUPLE DAYS AGO!
Please note that this is Whey Protein isolate, containing a greater amount of protein per serving and NOT the cheaper Concentrate!