An acquaintance who is a graphic designer has asked if I want to have some of my photos featured in a calendar she is putting together for a local real estate firm. They give them to their customers and distribute them locally each year. This year their idea is to use photos taken by local photographers. The only criteria is the photo has to have been taken in our city. She’s used my photos before for the local environment group‘s literature - always with my permission and with no fee - I consider it a donation to a worthy cause. For this she thinks they’ll want to use a couple of my abstracts and one I took of our city from the overlook. They’ll be paying a cost per image usage fee as well as photo credited on the calendar somehow. I have no idea what the typical fee would be for something relatively small scale like this. Thoughts? Besides the fee and photo credit, are there other things I need to consider for something like this ?