[Help]Salary Cap

Not as far as I'm aware.

Cheaters . . .

To each their own. It can also be used to update the salary to its current figure (since 08's default value is now outdated) so it's not without its more practical users.

so it's not possible to edit your budget for staff hiring even during dynasty?

It's randomly generated at the beginning of each offseason (including the first year) so I don't think so.

ok thanks,but do you have an idea how to increase staff budget legally? or how do you get more staff budget?

No, as I said it's generated randomly at the beginning of each offseason as far as I can tell. There's nothing in-game that you can do to influence it as you can with your salary cap space with your roster management.