I started last season and promoted from div 4 to div 3. And I am top of my conference this season and still in the cup, so I realise that it is quite doable. All I am saying is he has 2 options, 1 is to try and promote this season, and the second option is to stay in div 4 and try and train for a season and establish yourself and get some experience before advancing.
I prefer the first option of trying to promote rather than stay in the same division and that is what I did. If he also wants to go this way, he could get quite a bit of money for an 18 year old MVP (depending on his skill set) and with that money plus the 300k he currently has he could easily buy some great players which would virtually gaurantee him promotion this season.