1. It depends, as far as I know, someone spent more than S$3000 and someone else spent around S$1000. and it is case by case for time spending as well.
2. dont know, but i think it is quite difficult. Firstly, you need PRC's IC to learn driving in China(if I am not wrong); secondly, the traffic police may not accept that license even you can get it in China (since it is quite difficult for ppl to convert driving license after becoming SPR*. *they got driving license in China after they became SPR)