For those who may be interested I have just finished a DIY install of granite worktops. I bought two 2.3 metre lengths from an eBay seller for =A369.99 each. I bought a diamond blade for my angle grinder and set to work cutting as appropriate. The stuff is very heavy (100kg per sheet) so was very difficult to manoeuvre so had to get some assistance.
Cutting was the biggest challenge, the cutout for a ceramic sink took about 2 hours and is very dusty work. It was made more difficult due to the fact that the blade only cut about 3/4 of the way through, so I had to turn it over and do the other side.
The result are very nice looking worktops, total cost about =A3180, may have to spend 20 quid on some granite sealer.