Pricing question

Hi,
Today I gave my friend a photo that I had taken of her this summer. Regular sized and sepia toned etc. She showed it to her parents and then called to say they wanted to buy some enlargements from me. 2-3 copies to frame and send to relatives.

Now, should I let them just pay so it covers the printing cost, or should I add a little for my work? Professionally I feel like I should add some for my work, but it's her parents! We just took pics for fun, wasn't a planned session or anything.

The pics will be 15cmx20cm (app. 5x7) and cost maybe $7 to have printed.

/Claire

It may have been an unplanned session you did just for fun, but you still own the images and should make a little on the deal. Personally, I don't think asking $10 plus printing cost for each print is unreasonable.