Hello! New user hoping for advice about quoting for image reuse.

Hi Everyone,

I'm currently negotiating a fee with a large UK publishing house for use of an image I produced for a book jacket.

The image in question is one I mocked up with the authors (so not directly commissioned by the publishers - but the authors were working with the publisher at this time). Who now want to buy publishing rights to the image for their book cover for £400. I asked for £600 but they say it's a stock image they are buying. They also want me to make some alterations to the image before they use it. Should I push for somewhere in the middle?

They also want to reuse elements of this image in black and white form for chapter openers but don't know how many times and are offering a flat fee of £100 for this.

Should I be asking for a reuse fee for every time parts of the image are reproduced throughout the book or is it a case of one image, one fee, regardless of how many times they reuse parts of it?

I'm very confused about what is industry standard! Any insight at all greatfully appreciated.

Thank you freelancers!

Vivienne Darkbloom