if your a memeber on the sxoc? mazworx over in the states are doin replacement vvt sprockets for 280 delivered i think . Only nissan like to rape people for this part.

Like has been said tho if it doesn't annoy you just keep driving it won't do any harm i've changed mine for adjustable sprockets as i couldn't handle the ticking anymore have lost a bit of torque but my engine is fairly heavily modified so haven't noticed it to much.