They are one of a kind if I am not mistaken and they are in high demand by collectors. I agree with Faithcaster.
There are three of each piece of the 80k armor I believe. http://empireminecraft.com/wiki/empire-armor-leggings/
That's correct. Three full sets of 80k Members Armor were given out at the 80k member drop party, so, though not one of a kind, these are extremely rare!