I've gotten 5 in a single box from a Unity NM (Tiyanak). Surprising since most things that can drop in multiples cap at 3. Dunno if you can get even more.
One can buy Prize Powder for 10 accolades and NPC for 102 gil, which equates to 1 accolade=10.2 gil. Since refractives cost 15k accolades, people should not sell them for less than 15k (10.2) = 153k gil (in bazaar, for AH add a bit extra for AH fee).
