7 days in Guangzhou hotel cost

I would be travelling with family to Guangzhou next summers. we are four people, is it possible if we book one room.. is a family allowed to share one room even if there are four people.
secondly, how much would it roughly on average cost if we live in a 3 or 4 star hotel for 7-8 days in Guangzhou?
what are the cheap and esy transport options available to tour within Guangzhou?