Tamron 70-200mm 2.8 (DI) marco

im selling my beloved Tamron 70-200mm lens, its a amazing lens very sharp and fast, great for sport and weddings etc, am only selling due to ive changed camera kit and thou im still using my pentax aswell i dont need a long lens for it, its in very good condition and well looked after, comes with bag and tripod mount, has always had either uv of poloariser filters on it, (but they fit another lens so wont come with it)
been looking to see what price these go for but cant seem to find any 2nd hand atmo, so im open to offers of what people think its worth?
so "real" offfers pls?
(it is a £600+ bit of glass)
will try and upload some pic when i work out how