inlet manifold

i've been offered a renault espace 2.2 diesel o2 reg for a £1000 but they said they think theres a hair line crack in the inlet manifold which is causing a build up of pressure and trying to pop a seal does this sound plausable if so is it worth fix at this price for the car , because i've had one machanic look at it and he reckons these model espaces are nothing but trouble, is that right and is this a common fault on these , he said taking off the old manifold may lead to other problems because the cam belt is linked to the manifold and the injectors could be a pain to get out, so basicly is the car worth me paying a £1000 for it and doing the work or shoul i try and get it cheap , but will it be prone to other problems, please help as i have'nt a clue???????//////