I've never been able to find bergamots in LA after asking around for a few years. You can order a 6lbs crate at ripetoyou.com for $48 including shipping http://www.ripetoyou.com/index.php?op... and they also have Seville oranges, so maybe if you call them they'd be happy to send you 1/2 bergamots and 1/2 Seville.
I don't know where you can get Seville oranges locally though I've heard some urban legend that there were some trees on the Cal Tech campus and you could pick them up. I've never tried, but if you wander there, please report.
And, just to debunk another rumor, I was at E. Waldo Ward in Sierra Madre last month, and even though they do have Seville oranges for their own marmalade production, they don't sell them to the public because they don't have a license.
897 Granite Dr, Pasadena, CA