You can't buy peace actually for the individual it is relatively different because you can intentionally avoid certain things. If we are talking about peace in this context, I'm believing that it is being discussed in the area of fighting against the other and not the about health issues because if you also have health issues then you are not getting that desired peace.
But to be specific about the challenges of war, I think this is inevitable where two or more nations share boundaries. There has to be such struggle for terrestrial control of such areas and that peace is usually not gotten at ease and most times it is lost totally like we are witnessing in Israel/Palestine war, Ukraine/russian war etc and other troubles in the world including trade war.
Yes, you are absolutely correct and that is why peace is very important and valuable because without peace in ones life, that life will totally be a waste because the person can't rest and it can cause by poverty, health issues etc. That is why it is said that whatever thing we are doing in this life, we should do what is giving us joy and peace, because without it, one can't concentrate or focus to do things in a right way and if there is no peace in one's life, everything makes you restless and annoying.