Not really. It depends on you. If you want, ABC trekking can be done independently. You could hire a guide and a porter by yourself instead of going through an agency or not hire a guide at all. Although, not having a guide can be a little problematic during the offseason.
It really depends on you. Is it your first time in Nepal? How confident are you of being able to find your way around? How pressed on time are you? If you go through an agency, it will be costlier but everything will be planned. You will only have to come, trek and return.
