Amazon has the Autoglyms HD Wax at just under £27, which is close to some eBay suppliers. With Free Shipping.
Halford's price for this is roughing £44.99.
I have read quite a lot of reviews on waxes and this has received good reviews all around. It's the Pot wax and can last for a very long time (more than 18 months in some reviews I've read). Comes with the applicator and a Hi-Tech finish Cloth (£7.99 Halfords).
If you are one of them that likes to make sure your car looks sparkling, new or old this is the product for you.
I personally haven't splashed out on it yet. But saw most places sold it at £30 the cheapest.