Heather, welcome to the Disney Parks Moms Panel!
My family purchases the Disney Dining Plan every time we vacation at Walt Disney World. The number one reason I love it is that I can easily budget how much we are spending on food. I do not like having to watch and count every dollar that I am spending while on vacation. After all, budgeting is a stressful thing and the last thing I want is stress when I am in my happy place. It is very easy to track how many credits you have. You receive a set amount of snack and Quick-Service and / or Table-Service credits depending on the Dining Plan you select and how many nights you are staying. Each time you use a credit, you will be given a receipt showing how many you have remaining. Another reason I love the dining plan is when I am home in the 'real world' I look at a menu and my eyes go immediately to the prices. Sometimes I really want the steak but settle for the chicken due to mom guilt. At Walt Disney World, a credit is a credit at any of the restaurants that accept the Dining Plan. Therefore, if I am at a Table-Service restaurant and my Disney Dining Plan has Table-Service credits - I can have the Steak, the chicken, a salad - whatever my tummy is in the mood for! And finally the absolute best part - all meals come with dessert!
My son and husband are very big eaters. However, if you are a family that normally would share meals it may not make financial sense to purchase the Dining Plan. You could end up at the end of your trip with extra credits that you are scrambling to use, as they do not carry over for any future visits.
Wishing you and your family a magical vacation, Heather!
~Rachel