I just used paypal and saw where you could make a donation of $1 to something (I forgot what), and I don't think it was checked, and I did not check it. We will see if I am charged the $1.

I looked into the charge as they have a conversion charge. However the link I tried will not work. This is what i found about $1 charge; it may be a "Pre-Authorization fee" which is a one time fee that will be reversed as soon as your bank validates the card you used.
If you use a new card, or change any info on your account -- the charge may appear.
They really should make that clear when you purchase.

I used Paypal a couple of days ago and have not been charged an extra $1.

if you send money to a friend or relative then you pay the charges if its to a business then they pay them