This may sound strange, but you may want to consider Boston as one of the latest Low Cost Airports on the 'right coast'. Why? Well it is surprising the number of new (or expanded) LCC's are flying out of Logan. They include:
Air Canada's Jazz
AirTran
America West
ATA Airlines
JetBlue
Song
Yes, SouthWest Airlines is missing from this, but they do fly to Providence, RI and Manchester, NH - both one hour away and considered markets of Boston.