Trying to help out my parents for xmas, anyone have a 160GB+ IDE HDD they would sell cheaply?

My mother loves to take photos and my dad just learned to use a graphics tablet and they can't do either because their PC only has a 40GB HDD but is still perfectly fine otherwise. I only get to their place every 4-6 months to burn stuff off onto DVDs so they have room again but they don't know how to deal with the DVDs and end up just not ever seeing the pics again. I'd like to put a bigger HDD in their computer when I'm home for the holidays and I just don't have any IDE drives, and any I find are $50+. If someone has one they would sell for $20-25 shipped I'd be very grateful and so would they. An external USB drive would also work if someone has one instead.