Well, to get an end-game green straw effigy, you'll need an Amulet of the Mist, to get an Amulet of the Mist, you need to kill Shiro at the final mission in the Imperial Sanctum, to get to the final mission, you have to get through Raisu Palace...
Wait, what was the question again
O yea...

Price of a green straw effigy is generally equal to the current market value of an Amulet of the Mist which is currently being sold for around 20-25k me thinks...
Just stand in Kaineng Center D-1 for ten minutes and you'll probably figure out how much an Amulet is worth these days...
