There seem to be more options for 2a depending on where in China you are. These are two Shanghai-based options I got.
1200RMB card (the shop I bought mine from wouldn't discount off the price of the SIM, but was willing to throw in a mobile hotspot or USB modem for free) with local pricing:
96RMB/month for 3GB Shanghai-local+500MB out-of-town or 3.5GB Shanghai-local
Prepaid card for local use:
300RMB for 9GB/3 months
Once cut to microSIM size, they also work in iPhones for data and text, but not phone calls.