[Jgrace]

My $0.02:

Both buyers and sellers need to use clear language in these situations. “Grade” is not enough. “Grade numerically” or “grade authentic” should be used to set expectations. If a seller doesn’t provide that, the prospective buyer should demand that clarity.

That said, in this case I would have interpreted the language as a guarantee of a numeric grade, and expected a return if it turned out that the item was altered. I think that goes with the expectations of selling on this forum, and the trust that is required to make this whole thing work. However, I don’t believe the guarantee should extend to cover any grading costs (in this case, with the weak language).