Translation of the art book into English

It is necessary to translate from Russian to English art book – the volume of a large (947762 characters with spaces, respectively 23.7 author’s sheets). We need a competent translator who is ready to make a discount for such a large amount of work. Payment is possible in parts – for each chapter or every few pages. The project is not too urgent, so for the speed of work overpayment is provided. A prerequisite is the readiness to perform the test task for free - translation 1 page. Text.
P.S.: Give your price for all your work, not your rate!