The £150m that Manchester United have splurged on transfers is small change.
Petty cash.
The commercial revenues generated by the club are more than enough to get a few more players while they are at it.

In the latest full-year accounts released for the club, covering the 2012-13 season, United’s commercial operation pulled in £152.5m. However that figure has grown dramatically, with estimates suggesting that figure will be closer to £190m when the next full-year results – which cover 2013-14 – are released later this month.
Accounts covering the current season are expected to show commercial income closer to £240m when they are released next year.
If you lined up all their sponsors in a straight line it would probably reach the moon.
Here’s a look at some.

..and others

Globacom: Telecommunication services partner in Nigeria, Ghana, Republic of Benin
VIVA: Telecommunication services partner in Bahrain
VIVA Kuwait: Telecommunication services partner in Kuwait
Honda: Motorcycle partner in Thailand
Bakcell: Telecommunications partner for Azerbaijan
Gloops: Gaming partner in Japan
Truemove H: Mobile partner for Thailand
Truevisions: MUTV broadcaster for Thailand
PCCW: Telecommunications partner and broadcast partner for Hong Kong

and more here..