Cheryl, the prices are NUTS. You can find the services listed with prices on
http://www.celebritycruises.com/why...aWvA1b:12hdebdrn?pagename=aquaspa_and_fitness
I find the services are not of the quality I receive at home, and the prices at least 25% higher. Now if you regularly never receive treatments, and this is part of your "vacation experience", then go for it. I personally think they are well overpriced.
The Thalassotherapy pool can either be very relaxing, or quite an adventure, depending upon the seas. On turbulent days, you got shloshed around like a guppy (quite dangerous actually), on calm days, it's very relaxing. It's free. Hit it in the early mornings for the most solitude. It's basically a huge hot tub. A pool where you sit and veg out to the warm bubbles. I believe only M class and Solstice has these, but I could be wrong. Century does have new updates.
Spa food - there is no such thing as a "spa menu" in the main dining area. However, there is "lighter fare" each night. Next to the pool is a area that serves healthy lite foods (all day I believe)...I say I believe because healthy lite foods and cruising to me are not compatible or desirable. The Solstice has an entire "Spa Class" you may be interested in. Not my bag. Champagne and rack of lamb is more my thing.
Hope you find this helpful. Again, you can explore more details on the main Celebrity.com website.
Enjoy! Connie