Also they don't take inflation into consideration. So you could have bought an expensive item years ago,and with inflation technically lost money on it,but it would be classed as a profit.
So you buy something say a computer for £2500 and then sell it on ebay some time later for £2000 and you are expected to pay tax? Isn't tax meant to be on profit? In the case above you made a loss and still have to pay tax?