I was looking at Rotary lifts last year. If you have 13' of vertical space a Rotary should work nicely. They quoted me a price of $4200 installed. You also need to have proper concrete slab... 6" thick... but I don't remember the load rating.
My son works as a vallet at a Dodge/VW/BMW dealer. They use Rotary lifts in their shop. Sometimes they replace them and let employees buy the old ones really cheap.
Once installed, they can be unbolted and moved to a new location.
Scottsdale Lotus also uses Rotary lifts.
Rotary has a lift design that offsets the CG from the line between the pillars. That design makes it possible to open car doors after the car is raised -- another nice feature.
edit: Not sure about the 13' ceiling. It might be less, like 11.5'
Steve -- '05 Laser Blue, Biscuit, Sport/Touring, Starshield