Eddie, if you want to save on the high price of downtown hotels, I recommend Quality Inn in Gretna. Its right across the river from downtown and the bridge is now toll free. They only have a few rooms left so I recommend booking now. Its listed at $110 a night but I heard you can get a free shuttle back and forth across the river to the French Quarter and the cruise terminal and park while you are on the cruise plus the room for $129. You should be able to see the Jewel from the hotel.
You will have a great cruise on the Jewel. Its one of the few ships that goes to Costa Maya where you can take a short cheap taxi ride to walk the Malecon and visit one of my favorite hangouts. Fernandos 100% Agave is a local restaurant, nothing fancy, that serves very good local dishes and great drinks at a very cheap price. Last time we went there, 2 of us ate lunch and we had 2 margaritas each plus a couple of free drinks and the total was under $20. It is mainly locals and definitely not a tourist trap. They are on the first street from the Malecon.
On Roatan, the semi-sub ride is great.
On Belize an excursion to the Mayan ruins is a must.