I'm nearly certain that we told you that SIM was overpriced before you bought it. The China Mobile cross border SIM is currently a better product, and data only costs ~HK$30/G if you get on a plan (need HKID or cash deposit). But, if you fall off of LTE, and don't have a phone that supports other protocols, you're relegated to Edge.

Regarding buying SIMs on the street, the new laws have certainly limited the playing field, but the very closest 小卖铺 to me still sells pre-registered Mobile and Unicom SIMs (much higher prices than a year ago, though, and the SIMs usually aren't Shanghai numbers).