Those are lovely cultured freshwater pearls with circles. They are nice because the circles can reflect more iridescence than usual.
I am not sure what they would go for, because the circled ones aren't available as often. I guess retail with no clasp? $125. You could get a better price if you keep shopping or buy strands from a bead store, they could cost less to buy, but you would have to make it up. Made up- at least $100. Retail at some places, $150.
Get that restrung and wear it.