I am no tax expert, but I have no financial gain. The yard weighs what I bring in and pays me exactly what it is worth... We are even. No gain either way. Now, if my labor added value and they paid me for more than exactly what it was worth, then I would have to pay taxes on the difference between what I got paid and exactly what it was worth. Or, if someone were to pay me with scrap metal for work I performed for them, I would have to pay taxes on scrap metal I was paid with.