In-ground custom hot tubs cost more than above-ground custom hot tubs or pre-fab hot tubs. You can expect an in-ground hot tub to cost anywhere from $5,000 to $25,000. Part of the cost of these hot tubs is the excavation and preparation of the ground. Decks, decorative rocks, and other custom landscaping may be an additional cost. For a more accurate estimate for your project, contact us.