There is a lot more to it than most people take into account. There is a cost to the initial education requirements. I can't remember how much it was to take the salesperson education requirements, I took mine over 10 years ago, but you should look into that. Then, the dues. My local association costs me a couple hundred bucks a quarter, so that's nearly a thousand each year. You can call your local association and ask them what their due costs are. Also, you want to be able to open lockboxes to show yourself properties, right? That's an additional monthly cost (at least with my association). Then, you have to hang your license under a broker in order to use your license. Most agree to a split of your commission when you work under their license, some agree to only a monthly desk fee. If you aren't actually practicing regularly, but only using your license for your own occasional investment purchase, you might end up where the only type of broker that will accept you will be a desk fee type, which is another cost you should account for.
I'm not trying to talk you out of it. Run the numbers and see if it makes sense to you. In fact, like @Nick C. said, you could use this as an opportunity to get into practicing RE as a part time gig, making it financially worth it. All I'm saying is 90% of the time, it doesn't make financial sense to do what you are describing.