The seller gave me a price during the first contact (0.58 per unit). It seemed reasonable to me and I ordered a sample whose shipping cost $200US and the sample cost $300US. I received the sample and it seemed like a good product. When I am ready to place the order the seller tells me that the price is different (1.00 per unit). That's a 73% increase. We exchanged messages for 3 weeks, so I don't understand how the price could have increased that much. I wanted to do business with this seller because of the original price they gave me. But I was disappointed when they gave me a much higher cost per unit. I felt cheated and just felt like I wasted my money and my time.