Just lay everything you want in your Amazon UK cart, check it often (like every day) and as the price decreases/increases it will alert you at the top. I got most of The League Of Gentlemen DVDs for £3.98. I got Jam & Nathan Barley for £4.98. That's pretty cheap. Conversion rates are pretty good right now (about 1.5), so this is the time to buy. Don't wait until it goes back to 1.98 or over 2.
Older series are usually very cheap. Black Books Series 1-3 is £9.98...that's cheap. I paid £9.98 for each series.
Amazon UK is reliable and the shipping (as stated above) is very quick. I pre-ordered The Thick Of It Specials, it shipped early, and I had it in my DVD player April 14th...should have Ideal Series 4 on Friday.