PC death staff

ok i am wanting to buy a staff like this any idea how much i should be paying

either a shadow or ghostly staff

11-22 damage (req death magic) any req is ok
+10 energy
halves skill recharge of death skills(20%)
halves casting time of death skills (20%)

thnx

rough esimates cuz u dont hav these(low reqs)

shadow 250k+

ghostly 500k+

last 20/20 shadow I saw sell for a million.... (it was req 8 20/20 healing)

imo 400-500k+ shadow and at least around a million for the ghostly