Hi pennycuts,
The thickness of a mattress is just a side effect of the design and by itself isn’t particularly meaningful because whether a thicker or thinner mattress would be better or worse for any particular person will depend on the specifics of the latex (type, firmness, layers, etc.), your preferred sleeping position and your own somatotype and mass. Thickness is only one of many specs that are used to make different mattresses that perform and feel differently and that makes a mattress suitable for one person and not another.
There is more about the effect of thickness in post #14 here. For a latex mattress, 8"-9" is usually more than enough for most sleepers and positions, depending upon ability to customize layers, but ranges of 6" to 12" are quite common.
Regardless of how thick or thin a mattress may be … the most important part of the “value” of a mattress is how suitable it is “as a whole” for your particular body type, sleeping positions, and preferences in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) regardless of how thick it may be.
I hope that’s helpful to you. Are you considering a DIY project?
Phoenix