We have been to VB twice, and LOVED it..there are tons of activities for kids and families. They do charge, but it's relatively inexpensive. Cost depends on the type of activity. Crafts are inexpensive (around $8-12). They charge a rental fee for bikes, but if I recall correctly, tennis rackets and courts are free (just make sure you sign up early, as there are not many courts available). Kayaking and other activities such as nature walks are more expensive.
There are also kayaking tours and fishing charters nearby. Check out Squidlips for AMAZING food at a reasonable price