I'm mostly looking at people's experiences, where they have sourced recipes, and of course, how much their power bill went up since using the anova and whether that had a material affect on their usage of the machine.
My electricity provider is charging 26.73/kWh.
The Anova 1 uses around 100-250w to keep water around 60C in a stainless steel stock pot. Your power usage will obviously depend on your vessel's insulation and ambient temperature.
As with any electrical device, I look to minimize the time and power draw of it.
If you are looking for recipes, Douglas Baldwin (www.douglasbaldwin.com/sous-vide.html) and Serious Eats have pretty good and science based recipes for you to start with.
FYI if you use 250w to maintain temperature for 4 hours a day, you'll be looking at $24 more a quater. That excludes the initial time it takes to heat up the water (e.g. do you use hot tap water from gas/solar?)