If you are looking for a few diamonds for one ring, your local
pawnbrokers will probably have a selection of "estate" (used)
jewelry that are set with the diamonds that you need. Usually the
stones will be matched and the prices will be at or near wholesale,
with the added bonus of being able to see exactly what you are
buying before you plunk your money down.
It is much easier to find large quantities of smaller stones than it
is to find stuff in the 1/2 carat + sizes. Larger stuff can be
found, though, and often at ridiculously low prices! It would also
be VERY necessary to KNOW what you are looking for/at before you go
shopping. Don't neglect to ask if there is anything suitable in the
scrap jewelry pile, which is where the best deals will reside!
Be aware that most all the shops will have a little wiggle-room
built into the price tag, so do your best to pay 10%-30% less than
the asking price. Sure, you'll have to disassemble the jewelry, but
you'd be amazed what you can learn about putting jewelry together
by taking it apart! The gold can then be added to your
scrap pile for future shipment to your refiner to help reduce the
overall cost to you.
If, however, you need massive quantities, for multiple rings, the
convenience of having what you want shipped right to your door would
certainly preclude shopping, and haggling with, every pawnbroker in a
450 mile radius in order to get enough stones to make a production
run of a given ring.
Good luck, and may you enjoy the thrill of the hunt!
Steve (who would rather be out pawnshopping than running his own