I'd say between $9 to $15 to a reseller and low-xxx to end-user. However, keep in mind end-users are rare. The appraisal I gave I would not buy for but someone else probably would.
"Plus" is a nice suffix to have in a domain and got a good STR (Sell Through Rate) in general, but having "Graded" as prefix is not in sync that much. So, if you are lucky it may sell in the range of $1000 to $1500. Just my thought.