What to pay for photos like Met-Art?

Hi all,

I represent a group of artists creating modern art with a sensual “touch” – where a picture is typically built up around a picture of a nude woman. In this regard we have looked at the met-art web site, and many of the models there are interesting for our purposes, as there are several pictures in the style that is interesting for us; not the most vulgar pictures, but rather pictures of the ladies in more aesthetic posing, to describe it as well as I can (hopefully the meaning is understandable, despite my lack of the proper words…). In short, the goal is to present some pieces of modern artwork of high quality, and where those photos are an integrated element and where the result should be aesthetically elegant and – although not provocative – challenging. I wonder what we can expect to pay (on top of the membership fee) for a right to use such a picture commercially. The finalized artwork pictures are intended to be present on a website where people can buy them – either electronically or as posters.

I hope somebody here can assist – thank you all in advance.

Best regards