DL: SJC-SXM $433 rt ai (9253 mi, 4.7 cpm)
Saw a post on TFD about a SEA-SXM run for $430, so thought I'd give it a try from SJC and SFO.
Route: SJC-SLC-JFK-SXM-JFK-LAX-SJC
Sample Date: May 03-06
SFO-JFK-SXM has a lot more flights available at $430, but the cpm increases (5.0 cpm, 8526 mi).