People purchasing pine goods (10)
I believe the answer is:
belongings
'goods' is the definition.
(thesaurus)
'people purchasing pine' is the wordplay.
'people' becomes 'beings' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'purchasing' means one lot of letters goes inside another (some letters take possession of others).
'pine' becomes 'long' (to pine for something is to long for it).
'beings' going around 'long' is 'BELONGINGS'.
Can you help me to learn more?
(Other definitions for belongings that I've seen before include "stuff" , "Personal effects" , "property" .)