Would you sell pictures 'again' that you already took for a paid assignment?

Say, a venue hires you to take pictures at a party for promotional purposes. Then, the group of people who hired the venue approach you, asking for the pictures as well. What would you do?

I can think of several options:

• Send them samples and ask them to pay per picture
• Tell them to go to the venue, since you gave them permission to publish the pictures and they may want to be the only one with those rights
• Give them the pictures for free, as long as they credit you