With these kind of vehicles, mostly hot rods and resto-mods, it would be impossible for anyone except the original builder to even guesstimate the cost/value. Also, cost and value are usually wildly differing numbers.

With stock/restored/antique automobiles there is a fairly well known 'book' value, but even this is affected by collecting trends.

With modified vehicles of the type Ralph usually posts the value is always what someone is willing to pay(usually far below cost), and can be highly influenced by the current economy.

It is probably best just to fall back on the old axiom regarding yachts: If you have to ask, you can't afford it.