I did this for a group going down to NOLA a little while ago. I ended up getting a negotiated rate with AA. They'll not only give you 5% off whatever their lowest fare is, but also an additional 5% off if you book the tix 60 days in advance.

But the best part is that you get to use zone fares. If there isn't a saturday night stay, that can make a *huge* difference.

Alternatively, consider calling a travel agent. Sometimes they can do things, especially with the airlines sales offices, that us mortals can't do.