I believe the rules vary by local council - we used to go to one in Dorset where they'd sell you anything for a fiver or so. In contrast, the one near my parents in Berkshire isn't allowed to sell you anything (and it automatically becomes property of the council once someone places it on the ground and walks away). However, I'm pretty sure in the latter case £20 would convince them to look the other way whilst you recycled their waste.
As regards the bike above, well done. What always confuses me is how these people were obviously into cycling only X number of years ago, and yet now think it's worth nothing.