i am planning to travel in Guangzhou on 15th to 25th april 2015 to buy building materials

Well, for staying cost, it depends on the hotel level you booked. Generally speaking, it would cost around CNY500 for a four star hotel.

Attractions recommended to go: Yuexiu Park; The Pearl River; Sun Yat-sen Memorial Hall; Ancestral Temple of the Chen Family; Chimelong Resort; Zoo; South Sea God Temple, etc.