Yeah, it's a good idea to start from scratch anyway. Gives more time for reading etc and making sure you get things right. You can make mistakes with water quality (ammonia/nitrite/nitrate) whilst there are no fish in the tank, and then after adding fish you can start looking at phosphate/calcium/lighting etc whilst you're researching corals.
Might make an offer, but just noticed a lot of the equipment isn't included. Not as good a deal as I thought, seeing as the tank is scratched too. Seller must have thought £175 wasn't enough.