The absolute #1 reason I do not buy used equipment: The lenses I want are rarely reduced enough in cost from the new ones that I'm willing to risk it. I'm not going to spend $430 to buy a used lens that I can buy new for $470 (most recent example). When there's a lens I want which runs $1500 ballpark the used one better be more then $200 less... are that is QUITE often not the case. So I buy new.