The prices are the same for each ship. It depends on the type of massage you are wanting.
A standard hour Swedish style massage runs about $150 If you schedule one on a port day you can get it for under $100
There are also hot stone massage and one where they wrap you in a seaweed mixture... (not sure its really a massage)
If you can wait until later tonight, I'll take a look at our bill from our June cruise and let you know what the actual costs are.
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise
NCL Dream October 2006, RCCL Mariner OTS June 2007