what sort of price would it be to have air con fitted to my car?

It could of had it as an option at the factory but whoever bought it new didn't bother. I'm not too fussed about it to be honest but it would be nice to have, depending on how much it costs!

Any ideas?

And would it be a standard fit? i.e. using the original bits of the dash that BMW would have used etc?

THanks in advance