What' the incentive for a degree?

I'm 49 years old and have a great paying job as a supervisor in financial operations. I have worked hard to educate myself in accounting concepts, computer data bases and people management. The majority of the staff in my department have Master Degrees or double Masters. I never graduated from High School. I love my job, it's something that will keep me challenged for awhile. Except for my self esteem why should I persue a degree? I'm not sure that the finacial investment would ever pay off for me.