When I went to the Consulate office in May 2008, the only thing they said was available were multiple entries for $130 for US Citizens. China changed its policy in the beginning of 2008. Believe me, I asked for single entries since I was paying for 6 visas, for a family trip.
When I got my visa in November 2007, there were different categories with different prices (single, double and multiple). I am not sure if there are any further changes since May 08. But, those who are interested can easily look it up on the Chinese Consulate's website.
Godo... check on your visa and see what letter they put as the visa type. If there is a "(M)", then it is a multiple. It was explaned to me in May that they were still using the old xerox forms. You can check-off single or double, they charge you $130, but will automatically issue a multiple (M).