Hello.

Does having this box make my Soundabout more rare? How much value would it add? Thanks in advance for any replies

Box always make it add value.

VERY IMPORTANT; The serial number on the box MUST match the serial number on the respective Walkman. If not, someone has obviously mis-matched the box and Walkman, and that decreases the overall value.

I just checked and the serial # does match. Thank you for the info