I live in Huntsville, AL and have never been to New Orleans, LA.
Last week my employer sent out a notification of a local airline selling $15 one-way tickets to NO.
Airfare: $60.
My wife has a friend with a house in the French Quarter, they have agreed to let us stay.
Lodging: $0
The Bus from the airport to the house is $2.50.
Transportation: $10 total
Due to the above savings we will be much less rigorous in budgeting for food and events. Though walking around and sightseeing is free and will be a lot of what we do.
Food: ~$150-200 (I'm really looking forward to this and it might go higher, you can't skimp on food in NO)
Attractions: $100
Total Cost for 3.5 days in NO: $320-$370.
So $50/day/person.