it should be possible to set ticket price

+1

And ticket price we decide will influence the number of spectators and so the final income

Balancing price and attendance would be fun. And maybe, over certain prices, it could also affect the popularity of the club before the game 

perhaps a minimum and maximum price for tickets, so as not to abuse them,

but this will influence the club's popularity.

If it's tuned in the right way it's impossibile to abuse It, because the decrease in the attendance when you go over the optimal price makes the income go down 

Good suggestion

we re in real money game with real budget (accountancy)

if more local currency is distributed where come from the money ?

I wouldn't assume that custom ticket prices would make the stadium distribute more local money overall, it's just an additional thing to manage.

Anyway, they are paid from the global funds, using part of the money paid for the salaries, and even if there is a little increase in tickets cashflow it would be covered

-1 pointless...