I tried to buy a refurbished 1st gen blackbook 2 yrs ago at the 5th avenue Applestore NYC and the guys told me that they dont have actually refurbished macbooks but something like "refreshed" which actually meant that clients had returned them, were inspected and had not cosmetic or functional issues and therefore were sold with the opened box at a lower price (a bit higher than refurbished prices at the online store).
I did buy the "refreshed" (dont remember how much i saved) but i am tottaly satisfied, looked and worked like new and still does 2 yrs later!