Look from PHL if you're open to that option.
I took a quick look, and the award availability/prices aren't really any better. Either way, I'd have to be saving a bundle to be worth the hassle (not to mention 2.5 hours of driving + gas and tolls).
Or look for something like NYC-CLE-MIA, though that will make the cost higher.
Yup, looks like 24k per ticket RT. That's at least around $350 with a stopover.
Did u check LGA/JFK/PHL into PBI/MIA? Consider flying into MCO/FMY
Did u check kayak with airports nearby?
There's always Amtrak
I started with JFK/LGA - MIA/FLL. Eventually I looked at EWR and HPN too, but the only one that had any impact on prices was PBI, which adds a ton of direct flights to/from LGA and JFK. Ultimately I couldn't find anything with PBI that worked for us and saved us enough money to be worth the hassle. MCO, FMY, and PHY and others are all well over 2 hours away from where I am/need to be.
Anyway, I ended up finding the flights we wanted, albeit a slightly shorter trip (cutting off the second Shabbos and saving one vacation day at work) for $250 a pop, and it's nonstop between our preferred airports (LGA-FLL). The $400 I wrote in the OP doesn't really make sense (maybe I was thinking $400 total, that would be a pipe dream), but $250 isn't terrible.