Here is the info on the package handling fee.
BWV, BCV, and BLT Guests will be assessed a $10 fee per package processed. The fee is charged by IKON Office Solutions, Disney's contracted vendor at these resorts. If the trees are returned to IKON between guests, then an additional fee will be charged to the next guest. If the tree is stored by Bell Services, then there isn't a fee for the next guest.
Disney's policy on Bell Services storage is unclear. Some Cast Members say no problem, others report that they are not allowed to store the trees.
I guess that we will find out the hard way.