High Flow Air Conditioning install in existing older home?

Question:Would like to install central air in older home. Considering a thru-wall unit but it wouldn't help in the upstairs bedrooms. Someone told me about High Flow Central air that uses small tubing and can be installed in an older home. Would anyone know a ballpark estimate for an install in a 1200 SF two story home? One contractor told me $14,000! I couldn't believe it! I have access from the basement and from the attic, so I can't figure that the labor would be that expensive. Any help?

Answers:
If you are talking about a retrofit and you live in an area where prices are anything like California, that is not all that high a price.