Welcome to FlyerTalk.

My guess is that you probably won't get much lower (if at all) than the NW fare of $365.

I feel your pain - Southwest's ridiculously low fares have me conditioned to question any rountrip advance purchase fare that exceeds $218. We are spoiled.

But as we know, Southwest doesn't fly everywhere, and sometimes their lowest fare even exceeds $99 each way.

Sounds to me like you have done your homework. You've priced the trip using several sites - and found a number that is not sky-high. I'd probably just go ahead and book it if I were you.

You could substitute CLE or CAK for PIT and JAX for SAV and PVD for BDL and see if that changes the fare significantly. But then you would be facing significant ground transportation issues. I'd just buy what you have found.