The 50% rule
Take the repair quote and compare it to your car's value in good running order (check Trade Me sold listings for your model and year). If the repair costs more than 50% of the car's healthy value, selling is usually the better financial move.
Why not 100%?
Because one big repair rarely comes alone. A car that needs a $2,000 gearbox today often needs suspension, brakes or rust work within the year. The 50% rule builds in that risk.
The exceptions
- You know the car's history and everything else is solid — a single big repair can buy years of reliable driving.
- The repair is safety-critical and small — brakes and tyres are almost always worth doing if you keep driving it.
- Replacement cost — if buying another reliable car costs $8,000 and the repair is $2,000, repair can win even past the 50% line.
When selling wins clearly
Failed WOF with structural rust, blown head gasket on a high-kilometre engine, transmission failure in a car worth under $5,000, accident damage with airbags deployed — these repairs almost never pay back.
Know the other number
Most owners only find out the repair cost, never the sell price. A non-running car still has real value in parts and scrap. Get a free quote first — then the repair-or-sell decision takes two minutes.