Of course there's a cost in solar system, but if you're committed to using the system, it will pay for itself many times over. Savings on electricity can really add up over time. Buy local food. And clothing costs go way down. Maybe never, other than weddings and funerals.
Most full timers have one semi-formal dress outfit.
The rest is jeans, shorts, tee shirts and the like. A two week's supply of clothing is about all you need. Just pass a laundromat every two weeks. It will cost whatever you've got. But most full timers, after many years, will feel they've only begun to scratch the surface.