Is it 4x or 5x? Fist scythes are among the better brawling weapons, although I tend to favor sais. Real golvern is 5x if I recall; I am interested, if the stats are correct.
Most of my folks who brawl are ambushing rogues; they get a crit addition to ambushing attacks in any event, so the weighting is less of a factor there. I must say though, this weapon sounds unusual; ordinarily I'd figure the enhancement was temporary, but your longsong says not.
I actually haven't a clue what this weapon might be worth, but I'll toss in an opening bid for 1 million. It's probably worth more, but value depends on the demand, and I have no idea how many brawlers are around who might value such an item. Keep me posted.
