Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
On September 10 during Strikeforce: Heavyweight Grand Prix Semifinals, what was the PPV buyrate?

### Inputs:
table_name: table, columns: ['Date', 'Event', 'Location', 'Attendance', 'PPV Buyrate']

### Response:
SELECT PPV Buyrate FROM table WHERE Date = september 10 AND Event = strikeforce: heavyweight grand prix semifinals