They spent a cool $250,000 to use a portion of The Beatles' "Tomorrow Never Knows" on this week's Mad Men:

How 'Mad Men' Landed the Beatles: All You Need Is Love (and $250,000) - NYTimes.com (http://artsbeat.blogs.nytimes.com/2012/05/07/how-mad-men-landed-the-beatles-all-you-need-is-love-and-250000/?nl=todaysheadlines&emc=tha28_20120509)

Interesting article that reinforces a lot of what's been said here in the past.

And a few more tidbits:

http://blogs.wsj.com/speakeasy/2012/05/07/how-much-mad-men-paid-for-the-beatles/