It doesn't seem like a lot of money to me.
Even if you think of it as a just a pile of spares, that kind of money would not buy you a lot of spare major components from a scrap yard. The VIN plate in itself makes the pile of spares a vehicle.
When you consider the total cost of the project, USD4k is a small part. The kind of people who undertake these projects probably have at least that much invested in tools anyway.