The Lumia 800 runs to £195+VAT at Clove - a good deal for a phone that packs a Clear Black AMOLED 3.7" screen, 8Mpixel camera with Carl Zeiss optics and a beautiful one piece polycarb shell.
The Lumia 710 is the workhorse phone, although it sports the same speedy processor as the 800, a ClearBlack LCD 3.7" screen and replaceable rear covers. Currently this can be had for £99 from Carphone Warehouse or Asda Direct.
Finally the entry-level Lumia 610 is available for £79 from Asda Direct. Packing a lower-end processor than the other Lumias means its not quite so snappy, but still respectably fast and as a bonus the battery lasts a good two to three days of smartphone duties.