I believe Motorola also had $3B in cash when acquired.

Yeah, I'm not sure how straightforward it all was, but according to this article:

> At $12.5B, Motorola is Google’s largest acquisition to date. Google paid $40 / share in cash, but received ~$11 / share in cash and $8 / share in deferred tax assets. Thus the value ascribed to operations + patents was about $21 / share, or $6.3B, reflecting a multiple of ~0.5x sales and 12x EBITDA. Now adjusting this further for the $2.35B total consideration Google is expected to receive for the Motorola Home business, we get a purchase price of just under $4B for Motorola's handset business and patent portfolio (17K patents and 7.5K patent applications).

http://www.zdnet.com/googles-motorola-purchase-was-it-worth-...

So it seems like it would end up being $1 billion for a bunch of patents. The whole process has been rather weird, in the end.

They have also eaten large Motorola losses for quite a few quarters now. So it's not just the purchase price that is on the cost side.