But Jakks didn't make Yu Yu Hakesho figures to my knowledge (I know IF Labs did), and I think Toynami or something like that made the Inuyasha ones so I don't think that's a definitive answer...?
Irwin and if made hakusho, bandai and toynami inuyasha, company doesn't matter it just a convention thing to make ltd figures a solid color or other gimmicks like matted or furry or glow in dark ( my devilman is glow and ltd to 666 pieces)
A lot of exclusives like that only come in a bag I've noticed.
its because they try to make them at as little cost possible since they dont sell alot due to limited numbers, some DO have packaging though (usually the regular box with the cons sticker on it) and then some go the extra mile and make a custom/exclusive box/blister with it
I got some much needed ( though I didn't realize it) swords from king :D. had to cut the hole in Yamcha's hand bigger but that's one great looking sword to replace the one I never ever had that's way too small!