That would suggest the van has been used for around 5,500 miles per year or it has spent a number of years off the road. Either way, I would be cautious and (unless it is very cheap) suggest getting a mechanical inspection.

Vans are designed to cover 200k+ miles over six or seven years before being scrapped. There are some excellent and older vans on the road, but they do tend to suffer from a range of age-related problems that make them very expensive to maintain.