Costs are related to the local building codes (which vary) for aircraft hangars and materials and design features. Do you want an enclosed toilet and wash basin within the hangar, for example? Or a kitchen or living quarters? Are such even permitted?
Tee shaped hangars are sized to a bare minimum to accommodate a single engine or twin engine aircraft. Square or rectangular hangars are constructed to house one or more aircraft. (I know a pilot at SZP who has owned 55 aircraft, so far. He has three aircraft currently in his older galvanized corrugated steel hangar with sliding doors).
The General Aviation News (GAN) monthly publication has many ads for hangars for sale, often in airparks with adjoining homes. They also have ads for specialized builders of hangars. See www.GeneralAviationNews.com
With such a variety of hangars, sizes and hangar door constructions, there may be no typical hangar, as such. SZP in Southern California has some newly enclosed large metal deluxe hangars with full insulation, finished walls and concrete floors for sale starting at $300,000. Each have a new enclosed toilet and shower. One is finished with a very high grade fully equipped kitchen and bar lounge, showing the possibilities, located opposite the Aviation Museum of Santa Paula new hangar.
As a realtor, your first visit should be to your local county or city Building Permit Department for requirements-sanitation, fire suppression water availability, etc. Specialized aircraft hangar constructors can then guide you from there. Just bring money. Southern California does have a hangar shortage.