Saddle/seat post wanted

Hello hello, I’ve had my saddle stolen again. I’m very impecunious atm so I’m hoping to pick one up as cheaply as possible….or free if anyone’s feeling kind… Any condition is fine, in fact the scruffier the better! It’s 27.2mm which is pretty standard. Failing that, where’s the best place to pick these up cheaply? Should I just buy another stolen one on Brick Lane? Thanks!