Awesome! I've been wondering the same thing, and glad to see some answers here.
There are just a few things that have been left out. So let's do the rest of the math.
Cost of Running an Incubator (average per year, based on national statistics):
Electricity: $1.21
Water for humidity: $0.30
Replacement parts: $1.09
Egg cartons or trays for hatching: $0.73
Eggs for hatching: $250
Food and bedding for resulting chicks/ducklings: $85.28
New pens for extra birds that have imprinted on you so you can't slaughter them: $252.74
Second incubator because you want to run staggered hatches: $185.98
New brooding equipment for additional hatchlings: $150.17
More food and bedding for additional hatchlings: $87.36
More eggs to fill additional incubator space: $250
New pens (see above): $374.65 (because you decided to upgrade your design)
Food and equipment for new birds you can't sell or slaughter: $172.22
Expensive electronic toy for husband because he's starting to get worried about your "hobby": $336.27
Cabinet incubator because you now have too many eggs from your own birds to fit in your two incubators and besides, your husband now needs accessories for his cool new toy so he needs to butter you up: $632.60
Accessories for cool new toy: $516.23
BYC Membership because you absolutely must give yourself the user title "Hatching QUEEN" (and besides, what's another $20 when you're in this deep already?): $20
Total: $3316.83*
Watching a new life pop into the world under its own power: Priceless
* Note: These statistics represent averages in the first three years of hatching. Totals may go up in future years.