If you figure $50 a rim, especially for someone that would want to paint them black anyways, it's down to $600 obo.
But, then take off another $218.00 ... Tirerack's price for "a brand new identical tire for a spare (without rim)", [You need to post a pic of "brand new", no offense but after "nearly brand new" ...

].
So, if the spare looks new, and is also a BFG AT KO LT315/70/17, you're down to 4 used tires, for about $380. Although, these seem a bit tread-ware challenged, a fair price because they appear to have 20K to 30K miles left on them. And the BFG AT KO is an excellent tire.