A diamond broker is the middle man, he's the one that supplies/sells to the mall jewelry stores
Our's in is in Houston, we found while living there.
Every big city has them, usually there's a big secure building{s} they all are in, some are set up like real stores inside, others are more like offices.
Our guy is set up like an office, you go in, tell him what you are looking for and he brings out GOBS of goodies. Or he lets us go into the safe w/ him
They can also make anything custom you want as long as you have a brand name and style $# or photo..
Like if you like some Scott Kay design, tell them which one and they'll custom make one for you.
We have a local jeweler too now for less expensive items, but she wanted double what we just spent on eaarrings from our broker and that was w/ her 'special discount' for my DH because she knows he refuses to pay retail for anything.
Also, my earrings are slightly better clarity than hers were.