I have serious doubts that the ReptiBators will work well for chicken eggs, particularly as they don't have automatic egg turners. I don't know of any decent incubator that can handle that many chicken eggs for that price. The closest thing I am aware of is one of the styrofoam incubators. Murray McMurray sells a nice one with picture window, turning racks, and circulation fan for under $200 which will hold 70 chicken eggs. I have used these types of incubators before and always had a good hatch rate from them. You can check out the incubator at
http://www.mcmurrayhatchery.com/full_view_picture_window_incubator.html