You can surely argue your case as "party in person". But personally I would advise you to avoid it unless you are very familiar with procedural and substantial laws involved, as well as latches in law. Playing the game in theory and playing the game in arena is a very different matter.
If you have heart problem, would you entrust your heart surgery to a layman or a professional and experienced heart surgeon?
It is not always necessary to hire expensive lawyers. One can go for a lawyer that suits his pocket.