ALL OF THISIt's only £900 and you are worrying about the cambelt history! it's almost disposable at that sort of price.
Don't take this the wrong way, but If £900 is a lot of money to you, then I would advise you to buy something else. The RenaultSport cars aren't the cheapest of cars to run and if you can't afford to put good tyres on it, and keep on top of the servicing then you may as well buy a 1.2 Corsa.
That bit wont happen unfortunately, the engine has a note none too similar to a Massey Furgurson with 2 dropped cylindersnice sounding exhaust