The prices paid were a little steep if you plan to resell them, but if they are for personal use you did OK. I am sorry to hear the stories they told you, but really not surprised.
I was in Hong Kong this last weekend with Mia from my office. We arrived on Sunday for a morning meeting on Monday (yesterday) so we just walked around Tsimshatsui for several hours. There are a lot of shops that specialize in pearls (storefronts, not wholesale), and we were just looking through the windows at the mounds of hanks when one store owner came outside to try and sell us. He gave us this monologue about how the pearls were 100% Japanese and he imports them directly from a pearl farm, etc. etc... Get this, he was selling freshwater pearls!
Well, in my nice manner (nicer than I usually am here) I told him that the pearls were clearly Chinese freshwater, and I thought it was very dishonest of him to try to take advantage of what he assumed were tourists. His only response was that the pearls really were from Japanese rivers. Sad...
The pearls in the pictures have the classic look of medium-grade freshwater pearls. The shape, the luster, and even the pearl combinations are classic in China. They are sold as pictured to tourists at the Hongqiao market in Beijing in the $10 range. There are also a lot of foreigners that buy them as is for export and resale. That is likely how they wound up in the Middle East.