He is correct though - but there is no certainty or easy way to calculate.
The difference between a lease and a personal contract plan is that the personal contract plan has a fixed value at the end which you can pay to keep the vehicle, whereas a lease is just a long term hire car that goes back.
Generally, this fee (Known as the 'guaranteed future value') will be lower than the actual value of the vehicle, meaning you'll have some equity in the car at the end (ie, you'll owe less to buy it than its value). If you hand the car back to the finance company at the end of the agreement, you lose this.
But if you pay the fee and purchase the car from the finance company you can sell it and keep this equity. Alternatively, which is what most people do, you can use this equity when you trade the car in towards another. For example, if the guaranteed future value is £10k but the car is worth £12k in trade-in, you get that extra £2k towards your next car (The other £10k going towards settling the finance agreement).
To calculate the true total cost of a personal contract plan over the time you intend to have the car you need to be able to subtract the equity value from the total you've paid. But you can't easily do this as you don't know what it is. Historically it was fairly easy, just look at the value of an older version of the same model, adjust the figure for changes in model and a bit of inflation and you could have a reasonably sensible estimate of what that equity might be. But in the current market this is impossible - car values are so different to historical levels that its very hard to predict what anything bought now will be worth in 2026.
I don't like personal contract plans for this reason - the only certainty you have is the monthly payment, the true cost is difficult to calculate and all of the focus is on the monthly amount not the total cost which is the opposite of how any sensible appraisal of a purchase should work. People take them out because the monthly payments are lower as you only pay off the difference between the purchase price and the final value (Though don't forget you pay interest on the full amount borrowed). Typically this means people pay more for a car without realising because they focused only on monthly payments. This is why the motor industry likes them.
if you purchase it, the mileage doesn't matter. So if you know you'll pay/finance the balloon payment, choose the lowest mileage on the contract as you could do triple it and it won't matter as you're buying.
