Apparently it was bought just before the speed limit was imposed, and hasn't been used at all for the last two years. Quite apart from the optimistic price, I should think that the lack of use would make it one to avoid.
Speed limit aside, i don't see the problem if you want something stylish and only need a day boat, a Superhawk fits the bill. Theres plenty of similar stuff on the River Thames, broads etc... I actulay think it would make a very good buy, after all its only been in freshwater and if kept under cover probably imacculate. Five years isn't very old really so I don't see why the engines would have any major problems, it would be a different matter of course if it was on the coast.