Many flatbed scanners costing less than £100 now have a transparency adaptor and produce reasonable results. However if you want top quality and higher resolutions you will need a dedicated film scanner.
These are not cheap, although Jessops do one for about £400. They also do one for £200 but this has a lower max resolution. Nikon's and Minolta's range from £500 up to £3000. The choice is yours.
I think the Jessop models are Minolta clones from a discontinued range, at least they look similar.