I was very lucky when i got mine, a guy i work with just got a set of new chrome ones (set of 4) and he sold me his Hurricanes for £100 with a very good set of scorpions on them (set of 5) i gave him 1 old one for from mine as a spare and the rest i sold on ebay the wheel nuts and locking nuts all separate, i made out of it in the end,
Have a look at this and follow it, it would give you some idea what they go for then, but having said that it depends on the state of your rims and how much tread left on your tyres too, obviously the better they are the more you get