"Design is usually not about luxury, but rather, making the best use of available resources for any given project."
Buildings and cars are both designed and created across a spectrum of price, from low-end to high. Buildings are very different from automobiles in important ways... buildings are much more expensive, long term commitments that may appreciate in value rather than depreciate. But there are some metaphorical parallels between the cost of buildings and cars.
Automobiles and buildings share the same wide range in levels of quality. They also share similar quality factors, based on: (1) materials, systems, and construction; (2) function and performance; and (3) spatial qualities. Clients and architects must be aware of the wide range in levels of quality, and they must agree on a realistic quality level for which funds are available. 
The idea that architects are only interested in designing high-end buildings is just as silly as the idea that car manufacturers are only interested in building high-end cars. Design is not about luxury, but rather, making the best use of available resources for any given project. Design quality is critical across all pricepoints, for buildings just as much as for cars.
The idea that architects drive up costs is also a fallacy. A qualified architect will save clients far more than they cost in fees, both in terms of the initial project cost and ownership costs over time. If our budget is for a 'compact' car, we don't try to buy a 'luxury' car; we shop for the best value and quality we can afford. Following the analogy of the graph here, if our client needs to build in the 'economical' budget range, we will not design a 'grand' building; we will design the best building that the budget will allow.
 Problem Seeking William Pena, Steven Parshall Wiley 2012