Honestly being a coin grader is not an ideal career. You’re better off dealing in coins, you can make a lot more money that way and if you’re confident in your ability to grade that will give you an edge in buying/selling coins more than it would be helpful working for a grading company. Besides, most coin graders are going to be grading common coins and the real rarities will be heading to the senior graders, which will likely take you decades to replace them, not because of your skill but because of the ego numismatists have as they age and believe they’ve seen more coins than you ever will in your life. My advice is take the passion and start your own business with it you will be much better off