Hi Amanda,
Welcome to the Disney Parks Moms Panel and thank you for your question!
I have some good news for you: because children under 3 are Mickey Mouse’s special guests when they visit Walt Disney World Resort, they don’t need tickets to enter the Theme Parks or Water Parks AND there is no charge for them at any of the Walt Disney World Resort’s family dinner or buffet-style restaurants, including
Disney Junior Play 'n Dine at Hollywood & Vine at Disney's Hollywood Studios.
As for specific pricing, I unfortunately don't know what the cost for this dining experience will be in January 2016. Based on my understanding, the price can vary depending on the season (lower in less crowded months, such as January) but, in 2015, it has generally been between $15-$29.99 (tax and gratuity not included) per adult.
I hope my answer helps you plan your upcoming vacation! Please don’t hesitate to come back and see us if you have any other questions.
Have a Magical Day,
Lynne