Most cost estimates online are vehicle-only and skip the recurring daily spend — fuel, holiday parks, food, activities — that adds up to roughly the same as the rental itself. A useful planning rule for a couple in a mid-tier 2-berth during NZ shoulder season: budget NZ$450-650 per day, all-in. Peak summer (mid-December through January) adds about 25-35% across every line because the vehicle, the ferry and the holiday parks all price for demand.
Where the money goes — 7 days, 2 adults, shoulder season
Vehicle (mid-tier 2-berth, 7 nights): NZ$1,150-1,750. Fuel (1,400 km, diesel motorhome at ~12L/100km, RUC included): NZ$320-420. Holiday parks (6 powered sites at NZ$55-75): NZ$330-450. Food and groceries: NZ$280-420. One day activity (Milford cruise or similar): NZ$140-220. Total: NZ$2,220-3,260 before insurance excess buyout (add NZ$210 for full excess reduction).
What pushes the number up
Peak summer dates, premium-tier 2-berth, optional excess reduction, a Cook Strait ferry crossing (NZ$320-450 with a 6m vehicle), bike-rack hire, GPS hire (skip it — your phone works fine offline with downloaded maps), and child-seat hire at NZ$8-12 per day per seat.
What pulls the number down
Self-contained vehicle (unlocks NZ$0-15 DOC sites instead of NZ$55-75 holiday parks — saves NZ$200-400 across a week), shoulder-season dates, value-tier or budget-tier vehicle (saves NZ$400-700 on rental over 7 nights), and packing your own breakfast and lunch food from a supermarket on day one.
Note on prices. NZD ranges above are mid-2026 estimates from current rental fleet quotes and published holiday-park rates. Peak summer (mid-December through January) sits at the top of each range or above; shoulder season (March-May, October-November) sits at the bottom. We'll confirm live numbers for your dates when you send us a trip outline.