After 250 tatters, the best I came up with was Fast Cast +5% and Occ. quickens spellcasting +3%. Of these tries, top fast cast augment (6%) was the rarest to see, only popping up twice, of course either without the QC augment, or with a 1% QC. On the other hand, QC +3% occurred often. Good luck!
There are 3 reasons for the price of this item. materials (Siren's Hair x2, Behemoth Leather), t0 HQ rate (1/255?), and Extreme rarity with only a handful of these in FFXI, many of which might not even play the game anymore.
I am no clothcrafter so I'm not selling this, if I were to try selling this I would put it in bazaar for 50mil and never come down. pure rarity should bring someone to buy it.
This is one of the rarest items around. Pretty cool item though the Dalm+1 is really only an item for a real HQ addict as it doesn't give major stat boost over regular Dalm.