Famous people's autographs that are worth a fortune:

Vladimir Putin: $275 (£200)

Barack Obama: $480 (£350)

Madonna: $649 (£475)

Donald Trump: $1,025 (£750)

Ringo Starr: $2,050 (£1.5k)

Prince Harry: $2,390 (£1,750)

JK Rowling: $3,760 (£2,750)

Paul McCartney: $4,035 (£2,950)

Prince William: $4,790 (£3.5k)

Queen Elizabeth II: $6,100 (£4.5k)

Kurt Cobain: $4,000 (£3k)

John Lennon: $10,800 (£7.9k)

Winston Churchill: $10,800 (£7.9k)

Jimi Hendrix: $10,900 (£8k)

The Rolling Stones: $10,900 (£8k)

John F. Kennedy: $12,300 (£9k)

Neil Armstrong: $13,600 (£10k)

Diana, Princess of Wales: $13,600 (£10k)

Albert Einstein: $14,300 (£10.5k)

Marilyn Monroe: $15,700 (£11.5k)

Bruce Lee: $16,400 (£12k)

James Dean: $24,600 (£18k)

The Beatles: $40,000 (£29.5k)

Steven Hawking: $41,000 (£30k)

Steve Jobs: $54,000 (£40k)