they paid for it with the aguero money. they could've put that money into their debts, and then slid down to a mid table club. or they buy falcao and chase champions league glory, sell falcao + make some money through champions league windfall. what they've done is better than the alternative, which would be slipping into nothingness, being consumed by debt and really becoming obsolete.
http://swissramble.blogspot.com.au/2...mad-world.html
i'll link this again, it's a fascinating read.