We left out of New Orleans in Aug. 2005 (preKatrina). We stayed at the Maison St. Charles. It was $85 per night, and they will keep your car for the week of $5 per day. They give you a ride to the port (5 minute shuttle), but your on your own getting back to the hotel ($15+/- cab fare). Ask for the cruise package. Nice hotel for the money. It's across from Emeril's, too. If you're there for Sunday Brunch, it's worth every penny. Have also stayed at the W French Quarter. It's definitely not $85 per night, but very nice, though. Don't know if you can leave your car there for the week, but if so, it won't be $5 per night.
We just returned from a cruise out of New Orleans on Sunday...we had two nights in the city before our cruise departed and we stayed in a beautiful Marriot on Canal Street, within walking distance to the port. Excellent location as you can shop and also well within walking distance of Bourbon St., French Quarter, Jackson Square, etc...Best part of all, we booked through Priceline and got it for only $69. a night. What a deal!!!!
Hope this helps.