It looks scarier than it is, almost no-one pays up front anymore it's not a huge deal.
Take Transfermarkt as gospel price (which it's not but whatever), this is devoid of all player bonuses/ agent fees and all other bullshit. Of the 735million we have spent in the last 5 years, we owe 267mil to be paid over the next 5 which given the limited data we have is probably the last 3 years or so. Keep in mind, unless I'm reading this wrong, this is only spending.
Even though we are "shit at selling", we have sold 219mil worth of players in the same time frame, of which we are probably still owed 79mil (rough as shit guess) over the next five.
This figure will drop unless we go mad in the summer.