Have before me the Sept '97 wholesale price list from the Guide.
For a round, 3.0 ct F color VVS1 clarity diamond, the price is
$15,400/ct US. So total price would be $46,200. Above the
$10,000 level (highest markup level recorded in chart), retail
average markup is 35%. At the $45,000 level the percentage might
be lower. Also, this price is a guide, and you might get more
right now, as I hear large rough is somewhat scarce. However,
with a stone this big, if you are buying you might get a better
deal if the person selling needs to move it rather than hold it.
Many people tell me they can beat the Rappaport sheet prices by
20%, and I would suspect the same is true of the Guide. In the
end the answer to the question “what’s it worth?” is “it’s worth
what someone will pay for it.” I hope this is helpful to you,
and I hope you are selling the 3 ct stone, as 35% or $45,000
would be about $15,000, a nice profit!