Pricing is based on data collected and analyzed over several years to include cost of material, level of effort and overheads. Contractors are not cheap or expensive, each contractors pricing is based on overheads, level of insurance and legal structure. For example an incorporated business with employees will charge more than a sole. However if a sole is charging the same price as a small corporation - yeah that should be frowned upon.
For a non-trivial projects, I prefer to do a free site visit to properly assess the scope of work, thereafter I email a formal estimate and brief project plan on my letterhead. For trivial projects such as changing fixtures a site visit is not necessary - fixed costs apply.
I have an associates in business, associates in sustainable construction management, CALCTP certification as well as electrical training at Los Angeles Trade Tech.