I definitely do not recommend people becoming a licensed Realtor to save commission costs on their own investments.
Not only do you have to deal with expensive dues (I paid a minimum of $2,000/year on fees and dues alone), but every real estate transaction is a legal mine-field & lawsuit waiting to happen. You have to spend a lot of time, learning and training, and also most of the large brokerages will not let you broker your own deal. They have E&O insurance issues and if you screw up on your own RE transaction, you'll be paying for legal fees and mistakes out of your own pocket. It CAN be a potential nightmare.
You also have to disclose your Realtor status with every transaction you deal with. An in a lot of cases, you don't have as much freedom as if you were a regular investor/person who doesn't have a license.