Budget Travel - Milwaukee or Chicago to Miami

Hi everyone, just looking for advice. I'm looking for airfare in March from Milwaukee or Chicago to Miami or Fort Lauderdale. The best I can find is on Southwest for $440 pp RT. I'm wondering if that's about as low as the fares tend to be for this route and popular time, and I should just book now, or wait and hope they decrease.

Wait. Don't book yet. FLL should be cheaper.
Set alert on cheaptickets.com and monitor prices from Chicago and Milwaukee.
You should be able to get it for high $200s or low $300s.

Magic 8 Ball says: "use a sophisticated price prediction tool."

http://www.bing.com/travel

I've taken Amtrak between Chicago and Milwaukee for about US$11, then tack on a metro ticket to ORD or MDW and in total it should be less than US$20; granted you need about two hours, but if there are bigger overall savings, this could help.