Melissa,
Spa days are so much fun! You didn't specify which Spa you plan to visit but I highly recommend
Senses - A Disney Spa at Disney's Grand Floridian Resort. It's my absolute favorite and I always love to finish my spa day with a nice dinner at one of my favorite restaurants,
Cítricos. It's my definition of a perfect day!
To see a full list of services provided at Senses - a Disney Spa, please click
here. Since you are looking for something under $100, you may want to consider a Grand Floridian Signature Manicure or a Grand Floridian Signature Pedicure. Also, be sure to enjoy the wonderful amenities, such as the steam room or whirlpool spa. Please note that reservations are highly recommended. You may reserve your treatments by calling (407) WDW-SPAS or (407) 939-7727.
Spa Guests under the age of 18 must be accompanied by an adult and guest must be at least 14 years old to use the health club.
I hope this information helps you. If I can help you with anything else, please let me know.
Thanks.
~Ana