A museum wants my fossil, what is it worth?

A museum wants me to donate a fossil. They said it is a very important find and needs to be studied. I am wondering what it would be worth. Here is what the museum had to say. "this is an ancestral Juglans sp., previously undescribed and very important for science and as such should be in a museum to be studied. The stratigraphy of northeastern Montana fossil flora near Yellowstone River most likely is an analog of the floras of Glendive and vicinity. Hence the Paleocene at around 60 Mya an order of 15 My older than the Clarno Nut Beds and likely an ancestral fossil lineage. The photo has also been sent to Steven Manchester for additional clarification. Can you please provide accurate field collecting data? Additionally, the curators have asked me to prevail upon you that this specimen would be made available for study and description. The implications are significant especially considering the relationship to Clarno and the opportunity to better understand the evolutionary lineage of the Family Juglandaceae (walnut). Please contact me via PM if you have an interest in assisting this fabulous university and its paleontology department. if you choose to donate your great fossil there would be a few perks added as an incentive besides the great satisfaction of knowing you made a significant discovery that has potential impact on the evolutionary record for this genus. Additionally, it has been suggested that if this is in fact a new species the university has at its discretion the capacity to name it with you in mind. Say a Juglans cheleae for instance? Although the naming of a new species is not a guarantee I will personally pledge a dozen or so fossils from my personal collection for you to enjoy in return for your kind gesture should you elect to do so."