Marco:
It will run you anywhere from $85 to $160, depending on how extravagant you want to be. Shoes will run you extra as well as different vests.
Here is the link to Carnival's ordering page to give you the full run down, pictures and all information.
http://www.carnival.com/BonVoyage/De...Rentals&page=0
Rental does save on packing but if you are going to cruise a number of times it is worth considering purchasing. You can buy a good quality tuxedo and have it tailored for anywhere from $400 and up. Many people have purchased them for less. Tuxedo rental shops have closeouts for great deals on some great items. Unless you lose or gain a significant amount of weight you can wear them for many cruises. It's just something to consider but it's also another major expense for "this" cruise.
Have a great time on Liberty!!!!
Take care and you'll look great in the tuxedo.
Mike