The rift is better with washable VR Covers fitted anyway, you can also buy replacement face plates on Amazon.
If it is used, it's the equivalent to buying a used Simba mattress....and y'all have seen those suggestive adverts... i.e. these will have someones DNA on them....plus extras :S
Hot! (Unless you have an irrational fear of other people’s “face grease”)
I got mine from Leicester JL for £1 more and was "Grade C" but when I checked the box contents before buying it they near mint. The box was a bit battered but other than that it was fine. With JL they give you the 2 year warranty anyway too. There was no real signs of use and it appeared more like someone had issues setting it up (which I did initially as the sensor drivers were not automatically installing) They admitted to me that they don't set the price and that it's most likely just down to the damaged box (was just the sleeve) and it being a return. PS: It will be store specific and also mine did say "rebirbished" and not "used".
I have an i5 7600k and a 980ti so it's pretty good, but I wouldn't say a BEAST is necessary. Most games ask for a 970 and an i5 so a mid-high range PC will be good enough but I would imagine most people who look at the Oculus or Vive probably already have a good machine or plan on upgrading.