What is the fee?

How much is the fee if I am going to apply for a visa in the Embassy of China in the Philippines? Is it the same fee if I am applying for a minor (8 years old)? We plan to visit Shenzhen for a day tour coming from HK. Our return tickets are MLA-HK-MLA. Will it be cheaper if we apply for the VISA when we reached the HK-Shenzhen border?