I can totally sympathize. Southwest for mid-April is pretty high, too. But everything is. We were looking at April 13-20 and just the 13th has been $288 per person one way since I started checking on October 15. Tonight I ended up booking to arrive late on the 12th instead - it saved us just over $500, we'll get a value room for the night and still save $400.
We're also bringing our childcare person with us, but she isn't coming until class is out on Friday the 15th. Southwest doesn't have ANY Wanna Get Away fares that day and the later evening flight (not direct) on the 14th is $223.
I've looked at other carriers. Delta was $10 cheaper overall for our dates, but of course that doesn't include checked bag fees, and there are no nonstop flights.
Spring break here is the week of April 17th, hence the high prices.