I used the hova bator 1602n still air incubator which is a Styrofoam type I got it for $45.00, and I was happy with it but controlling the temperature to stay in on place was a little challenging, I think if I add a fan it will be a lot better, they have a newer model that comes with a fan you might want to try that one and its not $400 ebay has one for $75 hers a link
http://www.ebay.com/itm/like/230549308975?lpid=82
http://www.ebay.com/itm/like/230549308975?lpid=82