I think Diamond is very closely related to romance and tradition, over the years they have been many enhancement technology to make diamond cheaper, eg Laser drilling to remove particles, this will upgrade your S1 diamond to VVS1, minus the exorbitant price but somehow the consumer acceptance has been poor.

Why do people pay nearly double the cost of VVS1 from S1 when its near impossible to see the differences with your naked eye?

As mention Diamonds are so closely related to romance and the prove of love, so by cheating there will kill the romanticism.  Most people will still look for the real thing for a proposal ring. Maybe for normal accessories like earrings you can go for synthetic diamond, but until now I've yet to come across a single pc in malaysia.