Neves may seem like a bargain, but he certainly isn't the cheapest of all the wonderkids on this list. Hachim Mastour can be prised away from AC Milan for just £1.7 million, a price so low it's almost cheating. And with current wages of just £5,000, he'll happily develop in your reserves without costing the world. The 17-year-old central attacking midfielder is a must-buy purely based on his potential. He starts at 67 but could rise as high as 87, an enormous growth at such a low cost. Whether you're a lower side looking for current quality, or an elite team investing in the future, he simply must be one of your first signings in any saved game.