I often see refurbished items on retailer inventories, how exactly are these things refurbished? Do they get sent to a manufacturer's repair facility? Sometimes I wonder if refurbished just means cleaned up and put in a new pretty box. For those of you who have experience, what do you prefer, refurbished items or used? Which one has given you the best bang for the buck? What is a reliable source for used airguns/accessories and/or refurbished?