I like Elements as well. However, one of the reasons that Elements is
so cheap is because you can not batch run changes. In regular
Photoshop you can record actions, save them, then apply them to a
series of images or folders to apply your effects.
So in your case, you open image1 change contrast, change to grayscale,
save as image1_new. Then you can apply your steps to the whole
folder. 1 minute later the whole folder is done.
You can import older actions into Elements but really it is such a pain:
http://hiddenelements.com/actions_whitepaper.html
I've done it before but never across platforms. (you said the
photoshop 6 was on a pc).
It's a batch processing download to add onto iPhoto for macs. That way
you can apply your changes to multiple pages. It sounds like something
to check out.