By Nathan Ridley Lionel Messi’s first ever contract with Barcelona \- which was written on a napkin – is up for auction. It’ll cost you a pretty penny if you’re interested, though, with bidding starting at a whopping £300,000. British auction house Bonhams are set to sell the napkin in an online auction which will take place between March 18-27. It’s being sold on behalf of Horacio Gaggioli, an agent from Argentina who was an integral part of the deal which brought a 13-year-old Messi, who now plays for Inter Miami aged 36, to Catalunya. Bearing the date of December 14, 2000, the napkin has th…