Ever thought how much profit machinemart makes and how much floorspace they can afford to have in city locations.......
http://www.harborfreight.com/cpi/ctaf/category.taf?f=clearancesale&categoryid=10&pricetype=C&categoryname=WELDING%20TOOLS

Thats only a small section of the basic welders similar quality too looks to be the same china based slave shop churning them out.

mr brown no doubt takes his cut

I live a few miles from a Harbor Freight. They have a pretty good selection, the prices are typically low, and the quality is often good for the price. I haven't used any of their Chicago Electric welders, but the guy who does my welding tried one. He actually got it working pretty well, but it took more effort to keep it working properly compared to a higher quality welder. For the price, it's good for a hobbiest though. For heavier/production use..... I've worn out three 4-1/2" angle grinders from them in three years. I typically have three working ones (for grinding, sanding, and cut-off wheels) and one spare sitting on the shelf waiting it's turn. For $10.00 or so on-sale, they're not worth fixing and are barely worth changing the brushes if they wear out.

Change the $ sign to a £ sign, saves all that complicated working out. Then add 17.5% vat, job done.

I bought my 100 amp mig from Harbor Freight for $120. its worked pretty good so far.