Expensive in one word. I had A/C on a Mk1 and decided to fix it .. It was best part of £800 in parts alone when I stopped counting .. new condenser(radiator) £380, drier £40, pipes £300, pump to rebuild, then refill (well bought a Vac pump and gauges as same price but still £150). Before it failed I had tried a local A/C shop and they failed to fill/fix the leaks so that was a wasted £70 and it (yet again) destroyed my faith in folk working on my cars!
I took a/c out of another Mk1 to gain some bits but really the only bit usable was the pump.... but then if you are lucky the pipes would not be corroded .. my pipes and most used pipes corroded under the radiator where a steel bracket held an aluminium pipe which was continuously covered in salt every winter.. a perfect little corrosion cell which they designed out but this is hard to guess from the spares schematics.
I would buy a car with A/C .. and use that .. or at least harvest the A/C and resell the car for the same price. The A/C is never great and in Scotland it is useless most day as the roof down + sun hat is better .. I only got mine going for Europe after getting caught in 37C odd.. but there you just drive up the Alps!
