Hi
I strongly recommend the freshadama line. Right now they are a fabulous buy and good investment. This will not last! The largish 9-10mm freshadamas are over $1,000 a strand from PP: Here is the exact page.
http://www.pearlparadise.com/Freshadama-Pearls-9-10mm.htm
I have this page saved as a favorite because I want one of these SO bad!
These will appraise for far more and they are similar to natural pearls, which can not be had for under 10-15k for dinky ones.
When I say "similar", the only difference is that they were purposefully cultivated and tended and not wild grown. There are few new wild grown pearls, available, maybe none. Chinese freshwater pearls are solid pearl, just like the natural, wild-grown ones from over a century ago
The wild grown natural pearl business went belly up from overfishing in the rivers of North America and Scotland in the late 19th century and have not come back. The mussels themselves are endangerd by pollution and dams.
The entire 20th century was devoted to learning how to cultivate pearls and to producing pearl coated beads and developing that market to the everyday woman, because they made pearls affordable to the middle class for the first time in history!.
Then, in the 70's the Chinese started growing freshwaters without mother of pearl beads inside. They have recently perfected the art and science of growing these gems, as can be seen by the AAA and Frashadamas. They have not yet managed to market them as successfully as the akoya market does, but it will come and then they will cost far more.