I had an email this morning from a software company who want to use one of my images on some of their packaging. Naturally I am rather excited by this but I am wondering what I should ask for in terms of payment... I want to be fairly compensated for use of my work but at the same time I don't want to scare them off or be too greedy... advice from anyone with experience/knowledge in this area would be appreciated.

Here's a link to their site: www.codejock.com. In their email they offered to "make a donation" if I gave permission to use the image. I have already replied asking how much they plan to charge for the software and how many copies they might produce, as well as what sort of donation they had in mind and am awaiting a reply.