Hi steveevanskansas,
There is some more information in post #2 here about the number of layers in a latex mattress but basically more layers have more options available for customizing and fine tuning the mattress both before and after a purchase (by rearranging or exchanging layers). This may or may not be an advantage for specific people depending on how well a mattress with less layers or options available matches their needs and preferences in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences).
There is also more about layer and mattress thickness in post #14 here.
Whether more layers or other types of customization options are “worth” any extra costs that may be involved would depend on whether you are closer to the “I can sleep on anything” or the “princess and the pea” end of the range, the “fine tuning”, exchange or return options that are available to you, and the other parts of your personal value equation that are most important to you.
Phoenix