Rates are usually determined by the complexity of the text, and the turn-around time.
Complexity includes the amount of indexable entries occuring per page and the nature of the material. For instance, scholarly manuscripts are often denser than trade books.A per-indexable-page rate ranges from $3.00 to $5.00, depending on the complexity of material, with standard fees at $3.50 per page for typical trade books.
If possible, please send a sample chapter (not the introductory or first chapter) in pdf format, which allows me to determine an accurate per page fee.
If you require a quick turn-around time for your index, say, ten days for a 200 page book, rates increase.

