I actually considered it too. You would have to have a lot of rabbits to make it cost effective though. If cost is the main concern you should really budget it out... Start up costs include cages/water bottles or automatic waters/bowls/rabbits themselves etc then the feed to maintain them.
Also, am sure I'd get used to it, but I think killing them would be hard for me too. I could skin them and actually watched some informative videos on youtube on the subject, it's easier than i thought.
You'd have to have a TON of rabbits to have too many
New Zealand Whites, one of the larger popular meat breeds, weigh about 9-13 lbs. My two dogs eat approx. 90 lbs/month. I'd need about 2 rabbits a week. So, a litter every month or so could form the base of my dogs' diet (with other meats still for variety of course).
Perhaps checking out a rabbit farming book from the library would be a good first step?