Quoted from roar:
Just took a look at the majority of the Bally MPU AS-2518-35 games and sorted by average price from Pinside...
A couple of licensed titles at the top of that list... I'd consider Voltan an outlier, not too many people have had a chance to play that one, but you'd think their 5 released would be found in the top 10 of that list.
Even with code re-writes on them... I'm hard pressed to think someone would want to spend their asking price on the Mermaid edition when the original version is a third of the price or less for most of these games.
You have to keep in mind that the average price is not for completely restored mint games.