The staff might be an 'unwanted attribute', but it has collectors value. I wouldn't take the first offer that comes along because it can potentially get as much as 150e, or maybe more. My recommendation would be to put it into high end and see how bids go.
Don't see that staff getting 200e - zodiac staves are not that rare, casting is not the most useful for a mesmer, and illusion just has never sold well. 75e range maybe but don't see why anyone would pay 150e much less 200e. They still drop and more and more around... with the update on staves, a 20/20 just is not that rare anymore except certain skins.