It would be helpful if you indicated in the title which airport(s) you're interested in. There can be a very big difference in pricing, based on simple supply and demand and competition.
If you were flying from Hartford, I'd say it's almost impossible to get a good deal on Delta in the past year or more. That also means there isn't the competition, so SWA doesn't offer as good of sales as they used to and some of the basic fares are over $300 RT to start with (but there continue to be Ding specials .... it's just a lot less predictable and more gambling involved).