Plus, there's no way a football club could borrow at 5%, because they just don't offer a sufficiently secure investment.
Take the CFG as an example. This is arguably the most secure investment in the game. It is headed up by one of the world's leading clubs, has diverse global investments, is profitable at MCFC level and is ultimately owned by a multi-billionaire. Plus, the CFG money is used to invest in infrastructure, rather than make punts on footballing potential.
However, its borrowings bear an interest rate of LIBOR plus 3-3.5%. That's 8-8.5% overall.
I doubt an upper mid-table football club could borrow at less than 10%.