Possible Clues:

• Money outlay
• Divorcee confines energy outlay
• Writers in river demanding fee
• Cost of swans in the river
• Cost where pigs are kept in river
• Former writer ultimately queries expensive outlay
• Cost is 10p, we hear
• Cost of swans kept in river
• Cross when captivated by pen -- see high price
• Cost created by former lover with writer, she being vacuous