The AC system is very expensive to repair on these cars if they break down. If it's just a regas then this would cost about £50. Pre 1993 cars used the CFC gases. Cars using the old gases cannot be regassed until they have been retrofitted to accept the new CFC free gas. The retrofit alone will probably cost about £150. Then there are the other components - compressor, compressor clutch, condensor, evaporator.... . These are all very expensive items. If any of these require replacing or all then the cost can run to over £1000! The longer the AC is faulty and not used the more the chance of the parts in the AC system having to be replaced.