I am in the process of negotiating for a year-long exhibit at a major botanical garden (1700 acres) here in Illinois. The exhibit would consist of about 25 framed black and white silver gelatin 16x20 photographs that would be displayed in their research library. I am at a loss as to what to charge them for this project. Are there any websites, or other sources of information that deal with this? Or, anyone here have any experience they care to share? Thanks!