Google may have been a better shopper than Apple and its allies in the "Rockstar" group that paid $4.5 billion for patents from Nortel Networks, analysts at Jefferies reckon.

By laying out about  $12.5 billion for Motorola Mobility, Google will acquire about 17,500 patents plus 7,500 pending patents held by the Libertyville, Il.-based spinoff of the former Motorola, which dated back to 1928.

On a per-patent basis, that's about $560,000, Jefferies estimates. By contrast, the Apple-Microsoft-Sony-Ericsson-EMC-Research in Motion syndicate paid about $700,000 per patent for 6,000 patents from Nortel Networks, the descendant of the old Northern Electric, the Canadian arm of the old AT&T, which dated back to 1895.

Jefferies analysts Youseff Squall, Naved Khan, Sachin Khattar and Kip Paulson estimated Google, of Mountain View, Calif., is paying about $9.5 billion for Motorola Mobility's patents and another $3 billion for its consumer electronics business of mobile phones, set-top boxes and other devices.

Another plus for smartphone makers using the market-leading Android OS that Google had previously licensed to Motorola Mobility is lower licensing fees. That would tend to lower the cost of Android phones compared with the higher fees for Apple's iPhones and  iPads, which run only on Apple's proprietary iOS.

Google initially bid $900 million for the Nortel Networks patents in June but dropped out of later rounds that saw the value soar to $4.5 billion.

Also last month, Google paid an undisclosed amount to IBM for about 1,000 patents relating to computer architecture, "fabrication and architecture of memory and microprocessing chips" as well as online search engines. Unlike the Motorola and Nortel Networks patents, the IBM patents didn't include wireless devices. 

Google shares fell 3 percent to $538.30 in late Tuesday trading.