Hi Megan! I always suggest at least one character dining experience for families traveling to Walt Disney World. You do not have to over-do and book one a day as your child will soon not feel the magic that it is a special experience.
You can see all of the Disney
Character Dining Experiences at this site and it will include pricing for all three meals of the day. When selecting which to book consider if you are wanting something with the princesses or something with a particular character that you love. There are a few that offer experiences with the fabulous five characters and they are especially popular. Whatever one you choose it is best to reserve at your 180 day date as all character dining fills up fast.
Breakfast is going to be your most economical meal with prices ranging between 18-25 dollars for one adult. My favorite all time location is Chef Mickey and my favorite place inside a park is Crystal Palace in the Magic Kingdom. Hollywood and Vine and Akershus range around $30 and then Cinderella's Royal Table is the most expensive at around $45.
Lunch prices go up ranging from around $30-$48 for adults. Dinner prices then again will go up from there and range anywhere from around $31 at the Garden Grill to $55 for Cinderella's Royal Table.
Again choose carefully and choose an experience that fills you with the most magic for your vacation. If you are looking for a princess meal then I suggest Akershus but check out the site above to see what characters will be at what dining locations before you select and reserve.