Do you know what kind of ostriches they are (Reds, Blues, Blacks, hybrids)? Are you picking the eggs up in person or are they being shipped? There are a lot of unknowns here and I'll be more than happy to help you in any way I can.
With respect to the little giant incubator... I'm not sure that's going to work out so well. These birds are on the extremely difficult part of the easy to hard scale. If you don't have the correct equipment, you are going to have a pretty low hatch rate. In fact I haven't heard of anyone being successful with a styrofoam incubator. It's just that the ostrich egg put off a TON of CO2. If you don't have really good air flow and venting, they are going to die in the egg. I'm not sure your door being open or closed has anything to do with it.
I know that Natureform and others recommend a room that can refresh its air supply 4 - 6 times per day. And that's using a MONSTER size incubator.
I'm also shocked that the Cali operation is selling their eggs for 40.00 a piece. That doesn't make much sense to me. There is SO much that goes into proper care for these animals. 2 years before you see an egg. And the offspring? We are averaging over 2500.00 per bird that goes for meat production as we have the meat processed by a USDA inspected facility, packaged, and stored in a giant walk in here at the property. Then once a week we deliver meat to restaurants and wholesalers that are within a 200 mile radius of us. We are getting 300 - 500 for cured ostrich leather hides of first quality, 100 - 200 for the feathers, a contact in China buys the dried beaks/phallus/talons for 40.00 per ounce, and the meat trades for 30.00 - 40.00 per pound depending on cut and quantity. Average ostrich puts out about 50 - 70lbs of meat. So if you do the math there is a lot of money to be made with each bird. A 40.00 egg makes me go "Huh?".