Arsenal have one of the most valuable squads in world football right now. The Gunners have spent a fair bit of money over the years, but Mikel Arteta has done an incredible job improving most of them. Several Arsenal stars are worth a fortune on the market today. If Edu Gaspar decides to sell any of them, he will make a massive profit. One player’s transfer value has seen a huge rise in recent years – he’s now worth nearly 15 times what Arsenal paid to sign him. Arsenal star Gabriel Martinelli’s transfer value has shot upArsenal signed Gabriel Martinelli for just £6 million from Ituano in the …