Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_35206 ( "Date" text, "Event" text, "Location" text, "Attendance" text, "PPV Buyrate" text )

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

### Accurate SQL ###

SELECT "PPV Buyrate" FROM table_35206 WHERE "Date" = 'september 10' AND "Event" = 'strikeforce: heavyweight grand prix semifinals'