Of coarse personal worth trumps any guide.
Parts value is a separate issue, but obviously should be a consideration in price value of an item. The speed of markets today can easily leave you wondering what to believe a value to be. E.g. on auction sites it isnt hard to need 3 or 4 parts but find a whole example cheaper than than a few parts. Marx motors w/plastic shells are an example of how strange it gets. You can often find them cheaper with shell intact and running than bare and needing attention.
