I don't like to do this, but I will provide one example for comparison for a game which never made production, and what later occurred in pinball history.
The original Capcom prototype BBB (14 produced) average sales price $25K, and still is to this day.
IPB remakes sold for a little over $4K initially, which was higher than the standard game price tag of the time at $3250 for Stern games in 2004.
Today, the remake averages $15K.
Price difference is 5X from original to first days of remake. Today, the difference is still over $10K from original prototype.
The difference is not hundreds of dollars.
People MUST be able to differentiate between a prototype game which was produced/not produced, sample, and even early production. These categories are NOT the same thing, or have the same values.
No DW early production "wobble head" would be worth thousands of extra dollars, but one of TWO DW in the Bally cabinet with hologram/proto translite/artwork/lamps/and more is a different matter.