Costs will vary depending on your location, your herd size, and individual animals. Definately not a one size fits all type thing.
Some basic chores you'll need to do...
Feeding at least 2x daily.
Watering as needed, they should never run out.
Cleaning their pen of manure as needed.
Trimming hooves...needs to be done every 2-3 months.
Deworming...needs to be given as needed. Some herds rarely deworm...just depends.
Vaccinations...if you choose to vaccinate. Some people don't.
They should have a good sized pen with a dry, draft free shelter. Fencing should be strong enough to keep them in and predators out. They need good quality hay and goat specific loose minerals.