If i want to apply visa in Chinese consulate in Hongkong, how much is it for Q2 type?

If it's a single entry type one, the cost is 200 HKD. The express service fee is 200 HKD while the rush service fee is 300 HKD.

Genrally speaking, it takes three working days for the express application and two working days for the rush service application.

BTW, if you do not have HK residence permit, it's likely that you can't apply for mainland entry permit from there.