To const or to not to const (static readonly) that is the question

Lets discuss the following scenario: We have an assembly named [DomainModel] that has a class named [Person] that all of its properties are stored in a property-bag, in addition we have a const string that holds the key of the Name Property, this key is named [NameKey] and Its value is “Name”, so far so good.   don’t ask me why I use property bag this is just for demonstration purposes