Yo Mike,
I am not professional arbiter, nor am I an Arbiter drum expert, but think your snare might have been part of a portable, all pancake depth kit Arbiter made called "Flats" I think. I have a late 90's Arbiter AT (Advanced Tuning) snare that has the same halo hoop hardware as yours. It's more of traditional snare depth 12x5, but it tunes up great and sounds super. Mine didn't have the original strainer on it when I got it, but I found a Trick 3 position that fit without modification. I would like to see a pic of the strainer side on yours, I would guess mine would have been the same.
As for value, I have seen few like mine on Ebay, they seem to sell in the $200 to maybe $300 range. I don't remember seeing the pancake/flat ones, but I haven't really looked either. There might be at least one Flats kit out there that needs that snare to be complete, so it might be pretty valuable to that person.
Good Luck!