Looking for native english speaker to do proofreading of a short book for kids.

Hi,
I am looking for native english speaker (please, offers only from native speakers), who will do proofreading of a story for kids. would ask you for proofreading/correction of one page first (1800 characters incl. space bar). If I will be satisfied with your work I will contract you to do proofreading for the whole story (31 pages, 70 000 characters). Please let me know about the price for the test-proofreading of one page as well as total price (and time needed to complete this task) for 31 pages. Please make a bid for one page proofreading first! Thank you and regards!