What does a day in New Orleans cost?

So what would you expect to spend on a day in New Orleans
TRANSPORT:
Budget option transport to the JazzFest is via public bus or the streetcar - both US$1.25 per trip. I normally get the bus. They even had some new air conditioned ones running this year.
The upmarket option would be sharing a cab which is a flat $5 per passenger from the Quarter. So if someone didn't want to walk a few short blocks to the bus stop then that would be the go.

FOOD:
As you spend most of the day at the Fest, this is where a lot of eating (and drinking!) takes place.
Costs for a small plate of food (ie: jambalaya, po boy) inside the grounds are around US$5 - 6. Ranging up to $10 + for a mixed plate.
You would normally eat maybe 2 to 3 of these in a day.
Beers are US$4 - 5 for a can. Wine is $6 for a glass.
So depending on how much you choose to eat / drink then a day it can be anything from, say, $20 up to $50. I don't think I've ever done much more than $30 personally, but I don't drink much during the day!

EVENING GIGS / EATING:
Once again, lots of options.
The French Quarter has some really good casual eateries where you can pick up traditional Cajun / Creole food for under US$20 for a main. Blackened Fish, Gumbo, crawfish done every which way etc. Or you can spend a lot more at some of the really upmarket restaurants, but you don't have to spend up large to still eat well.
One of my favourites is a fab wee Gambian family-run restaurant that does gorgeous African cuisine, and all the mains are around $16. Hard to get into tho' - very popular.

Clubs in the French Quarter - well some don't have cover charges and some do. Depends who's playing, but for a quality act you should expect to pay at least $10 - 15, with some shows being considerably more than that.
Having said that quite a number of bars have no cover charge at all if you just want to go and drink and boogie out on Bourbon St.

So in summary, you can certainly do JazzFest on a budget, maybe as little as US$60 - 70 a day if you're not a drinker.
But to do it comfortably the a US$100 plus is more the go.
Cheers
Paul