2002 Fiat Punto knocking from gearbox..

Hi all. I have a 2002 Punto 1.2 8v with 68k miles on the clock. Over the last couple of weeks a knocking has become louder from the gearbox. It knocks when the car is stationary but disappears when the clutch is pressed, and creates a 'droning' noise when driving. Does anyone know if the gearbox is scrap? I've changed the gearbox oil with the recommended 75w90 gear oil, and problem is still there. I know that if the box has gone I may as well put a new clutch in, but as I'm an apprentice on £3.40 an hour it's going to be a struggle! I can send a video of the knock via email to anyone who could verify the problem for me! Thanks