At what point will a used van become expensive to maintain?

I'm looking to convert a Renault Master High Top LWB into a horsebox. Should I buy four to five year old van with 200,000 miles or an eight to nine year old van with 120,000 miles? Also, at what point...

Our BMW 1 Series is showing a DPF light - is this because we only use it for short journeys?

I recently bought my son a BMW 1 Series for his 18th birthday. Soon after the filter light came on. We took it to a garage to be looked at and the turbo was burnt out, so had to be replaced. We also had...