In a similar vein to the Duluth pack you might want to look at this one from LL Bean for less than 1/3 of the cost of the Duluth pack:
http://www.llbean.com/webapp/wcs/st...oreId=1&catalogId=1&langId=-1&from=SR&feat=sr
I'm not sure if LL Bean has a presence in the UK, but it's an old and well known outdoor supplier in the US. As with many things, their older stuff is often better made than the new, but still they do good work. I used to live in their wet weather boots when I lived in Alaska.
These packs are made in China, however, and I can assume the craftsmanship -- while certainly serviceable -- won't be up to Duluth standards.
But for the money, it looks pretty tempting to me....