Sammy
Like many other answers, it depends. The primary question that would have to answered deals with whether the company you are working for is employee based or independent contractor(IC).
There are still a lot of appraisal companies using IC's, so the fee split can be higher with, but you you have to pay your taxes and you get no benefits. With an employee based company, the company pays 1/2 the social security, as well as unemployment insurance and in our state Labor and Industries.
I run a company that is employee based and start the trainees out at 30% and after they are licensed/certified, it goes to 50% with possible increases in between. We buy all the supplies and equipment.
There are a wide variety of ways to run a company. Some will provide everything and others will provide nothing and still others that will provide the equipment, but charge you for the use. I have heard of people who charge rent for the office space.
So, listen to the potential employer and ask questions.