What things should I check when buying a second hand van to make sure it is still in good condition? Additionally, please tell me which items would be most expensive to fix if they were not in good condition
When buying a second-hand van, there are several things you should check to ensure that it is still in good condition:

1. Exterior and Interior Condition: Check the van's body and interior for any signs of damage, rust, or wear and tear. Make sure to look for any signs of accidents or paint repairs, which can indicate that the van has been in a collision.

2. Mileage: Check the van's mileage and compare it to its age. A van with high mileage may have more wear and tear, which can affect its performance and longevity.

3. Service History: Check the van's service history to ensure that it has been well-maintained and serviced regularly. A well-maintained van is likely to be more reliable and have fewer issues.

4. Engine and Transmission: Check the engine and transmission for any signs of leaks or damage. Look for any unusual noises or vibrations while driving, which can indicate a problem with the engine or transmission.

5. Tires and Suspension: Check the tires and suspension for any signs of wear and tear. Uneven tire wear or a bumpy ride can indicate suspension issues.

6. Electrical System: Check the van's electrical system, including the lights, radio, and dashboard. Make sure all components are functioning properly.

7. Test Drive: Take the van for a test drive and pay attention to how it handles, accelerates, and brakes.

In terms of items that would be most expensive to fix if they were not in good condition, the engine and transmission are typically the most costly to repair or replace. Other expensive items include the suspension, brakes, and electrical system. It's important to consider the cost of repairs and maintenance when purchasing a second-hand van to ensure that it is a worthwhile investment in the long run.
At what age do delivery vans start to show defects?
When a vehicle is regularly used and cared for, large-scale internal defects are a matter of mileage rather than age. Most auto manufacturers with specific maintenance packages for vans have them at specific milestones, such as every 10000 or 40000 miles for different checks, repairs or replacements. As a potential purchaser, using the mileage as a proxy for internal wear is a good strategy, especially when coupled with the full maintenance records, and potentially a third-party multi-point inspection.

Deriving a more general heuristic, delivery van maintenance costs often tick up after the fifth year of regular service use, indicating more frequent repairs to more expensive components. Thus, the median delivery van starts to show defects around its sixth or seventh year of age.