PS - how expensive is it?

Now I have a possible replacement material, I can actually go to bed, lol. I've been reading up on alternatives to mercury virtually all night - so much to digest.

Thanks everyone for sharing what you've leant, it's a great help to those of us just learning. I feel quite alone on this, which is why I am posting so much. Thanks for listening <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />