According to the U.S. Bureau of Labor Statistics (BLS), the median annual wage for real estate appraisers and assessors was $51,860, as of May 2015. The top 10% of all appraisers earned more than $97,080. (*Median means 50% of population is higher and 50% of population is lower)
As a comparison, the median compensation for all US workers was $28,851, as of 2014 according to the U.S. Social Security Administration (SSA).
That means that the median income for a real property appraiser is well above the national median that includes every occupation. Real estate appraisers are paid well. Since a large number of appraisers are self-employed, those appraisers are in more control than salaried employees of how much they can earn.
Trainee real estate appraiser typically earn a portion of each appraisal they do. The amount is a trainee earns per appraisal is determined by the supervisor. Therefor, once a trainee earns their appraisal license, their earning potential increases significantly.
It should be noted that these statistics come from United States government agencies and are national averages. The median wages differ by state, as a result of many factors. To get information about the specific state that you are interested in working, please see the BLS geographic profile for real estate appraisers.