China Unicom is now accepting pre-orders for the iPhone 4. According to a Wall Street Journal report, the handset is priced between 5,880 yuan to 6,999 yuan (roughly $874 to $1,040), in line with what the carrier charged for the iPhone 3GS when it launched in China last October. The report states that sales have picked up after a slow start, but are still hampered by China Unicom’s exclusivity. Citing a surveys of young Chinese mobile subscribers by CMR, the report claims that potential Chinese iPhone users are reluctant to switch to China Unicom due to perceptions of poor service quality, the lengthy required contracts, and because they don’t want to relinquish their China Mobile phone numbers. Analysts estimate that millions of Chinese customers are instead using gray market iPhones without 3G service on China Mobile; Apple also sells the iPhone 3GS unlocked in its Chinese stores.