How do you put a price on your project car?

I was just curious of how others put a price on a car that they built. If they want to sell it.
My guess you'd have to research what similar cars sale for in the area you plan on selling it, not what their asking. Like a guy around me been asking $35,000 for 3-4 years now for restored 340 Duster, he may get it some day but obviously not a selling price.