Given you probably have a very reasonable income, I'd look at it one of two different ways.
Where are you now, job wise, and where do you want to be? Are there new skills/technologies you want to learn, or that would be useful at work? What do you need to work on to get to the next level?
Or the startup route, do you have any ideas that you want to work on, or do you fancy being the CTO helping ideas people bring their ideas to life? You have to be very lucky to make money, but the skills and experience you'd get would be invaluable.