I recently bought the Hova bator Genesis 1588 from "Incubator Warehouse". $119 before shipping. I would buy the biggest you can afford. If you buy a smaller one now, you'll just wish you got a bigger one later. Too, you can always hatch a few eggs in a big one, but you can't put alot of eggs in a little one.
This is my first hatch in 1588, so I can't say whether it will improve my hatching skills or make up for the lack thereof. So I can't recommend anything, just think you should get the biggest you can afford. "Incubator Warehouse" was cheapest for the incu I wanted, as I was specifically searching for the 1588. You may be looking for something else and like "my momma told me , you better shop around".
All the best
Rancher