When it comes to my home system, I have kept every box. Main reason is if they need to go for repair or service. An example is the Nakamichi CR-7 goes into Bowers & Wilkins Nakamichi every 2 years or so for a full service. The last time my Pre-Amp played up it had to go all the way back to America to be fixed, so for my home system I will always keep the boxes.