Not cheap, these harbingers of spring, at $10, $20 and $30 bucks a bunch, but this stand at the Santa Monica farmer's market this week was mobbed.
The lilacs we see in SoCal were bred for our mild climate and one of the things we gave up, since we don't have the annual freeze the Eastern varieties require, is the fragrance. Oh, you'll get the bit of lilac scent if you get close enough and breathe in hard enough, but it's faint.
More lilac info in a piece I wrote in the LAT, and at the Descanso Gardens web site.