I've never quite understood why Voodoos are worth less than Konas, being as they're pretty much identical, but the fact is that they don't have quite the same reputation and they are worth less.
I think a Hoodoo is equivalent to a Cinder Cone/Lava Dome - made of double-butted generic cromo with a frame weight of 4.8 or so. Without seeing a photo, a spec list or knowing condition a proper valuation isn't possible, but subject to all that I'd guess £150 is tops and only if well-presented.
My other guess is that if you sell it now, one day you'll regret it.