Just as info. Getting an appraisers' license is a little more complicated than you think. There's schooling, and a lot of, it depending on what "level" you'd like to be at.
I can't remember all the details, as I've looked into this before, but it's more than putting a price on a house. The education was pretty time consuming, after that they want you working as an apprentice with a experienced appraiser for 2 years I believe. There was a lot involved. I think you'd be better off learning about REI right here.
Just my 2 cents.