Yes but at the same time what indicators are there for you to see in a 13 year old boy that he could even be remotely good enough for the first team 10 years down the line. I'm not a fan of paying money for under 16's because they haven't even left school and its a big risk.
£3M would only be if he goes on to make a certain number of first team appearances / international appearances. The actual fee would be minimal, this is going to happen a lot more now with the new rules brought into place. Small fees upfront and larger fees depending on development for under 17 year olds not on pro contracts.