I think important issues would be.
how many eggs?
Lots of babies makes lots of work.
how long have you been into poultry?
if you are only beginning a modest incubator will give you a chance to learn and decide if hatching eggs is for you.
There wouldn't be anymore then a dozen at a time.
I have kept poultry for at least 10 years now although I am still only new to hatching and baby chicks. I got into ducks about a year ago now and i'm still learning them and their ways and I would like to breed some babies from them. I'd rather hatch the eggs in an incubator then take the babies from the mum in case I get the timing wrong. A modest incubator would be about right. I have Bantam indian Game and Bantam Silver Appleyards i'd like to hatch and the odd chook egg wouldn't go astray.