you have responded perfecly ,he has only paid for goods but not for postage  it looks like a pick up for sure , which you have stated   as a option,but because you dont have stated ,  must be picked up by a certain time ,they can pick it up in lets say 3 months time ,i am not sure the exact time but after that time, i think 2 months , you can notify the buyer that you will relist the item after a another 30 days notice to the buyer.

anyway dont worry about it ,its a very small parcel just put it up on a shelf ,you have been paid for it.