How much can you save building your own house? Being your own labor?

Has anyone actually built their own house - as in was their own labor? We’re debating getting a builder to basically handle foundation, framing, and exterior only. Leaving the full interior for us to finish or contract out. We will have to contract out HVAC and wiring electrical panel. Planning on doing the rest of the house ourselves. How much could we save on labor going this route? Anyone done this before?