[GFK_of_xmaspast]

" There is a reason a flawless 1 carat natural diamond might cost you somewhere around $18,000 and a flawless 1 carat synthetic diamond will cost you maybe $100-200. "

That reason's quite probably "the deBeers marketing machine". The only difference between a synthetic diamond and an actual diamond is one's grown in a cleanroom and the other's dug out of the ground by exploited miners (and sometimes actual slaves).