Well, I went to the China Mobile store to see how things would work. Their cheapest monthly plan is RMB 8 and it comes with 30 minutes of voice only. Data is additional at 20 or 30 RMB per 1GB - 2 employees gave me different numbers. The ladies said that is expensive and gets chewed up by WeChat in no time. For those who are used to North American data, this is a bargain
The lady at the counter said that you can receive SMS outside Mainland China with no additional charge but you have to enable roaming, which she said is free. She said one can put a bunch of money in the account so they just deduct RMB 8 every month.
She also said that there is really no traditional prepaid SIM anymore. If people want one upon arrival, basically they have to sign up for the 8 RMB plan then add data for the duration.
It is kind of interesting there is no literature on these plans they can give you to confirm what they have told you. I guess I will Google, I mean Baidu, later.
Now off to more sightseeing....If I pass a Unicom Store, I will go in and ask too.