China Unicom plans to charge 2,500 yuan, or roughly $366, for the 8GB iPhone 3G when it launches the device in China, according to a new report. Chinese-language cnBeta reports (Translated Link) that the company will be offering that price with a two-year contract agreement, at a minimum monthly rate of 186 yuan, or roughly $27. Based on numbers reported in an earlier article, this would place the iPhone 3G below the cost of most high-end phones on…