i won't give the owners of the arena the money, maybe we could give the payback like that ...
But i like a fix sum in relation to their salary most, because thepayback could be very different. If you play with your U21 team in the arena from Laim, you would earn good money and it is lucrative. If you play in the biggest arena from Al Jazair(just an example), you will get pretty less money.
that`s why it would be more fun and more responsibility for coach, cause as far the team goes in tournament as more money get owners... And there almost wont be left any place for situations then coach takes player from friends or his team, cause he would have to show result.
but together with this there should be implemented system how to fire the coach for community... maybe in countries there coach work is rated from at least 50 votes he would be fired and second place winner would be appointed as a coach if popularity would be less then 10%. This could happen just once per season so max rotation would be 3 coaches per election period.
but it is hard to calculate with it, i think good NT players find easier a team if you could calculate how much money you will get back. And with this system i believe the strong nations getting stronger then the weak one, lets see nigeria for example.
In my eyes their NT make a good job, but in africa cup the infrastructure is usually weaker then the one from Europe or America. So this team get rewarded less money, even for excellent coaching + and gs manegement which will lower the motivation to train their players(because you get only a part of it back then italy).