I'm pretty sure a vegetarian diet would be cheaper for me, since wholesome, kindly raised meat is madly expensive. The thing is, even if I became a vegetarian, I would not feel right imposing that choice on my dogs and could not impose it on my cats, so I'd have to buy meat for them regardless. And since I'm not rich enough to feed them meat from nicely raised beasts,* and the bulk of the meat I buy is intended for them, I would continue to feel like an immoral (in some ways) monster even if I ceased to eat meat altogether.
*This morning, for example, I bought $20.75 worth of chicken leg/thigh quarters, which will supply my dogs with breakfast for about two weeks. The same amount of chicken bought from the local organic farm would have cost me almost $100. The meat I need for their supper would similarly cost me about $100 for a two-week supply of what I think of as good meat, whereas I could get the equivalent amount from the supermarket for $28. Thus it would cost me $200 every two weeks to feed them good meat, compared to $50. Add another $260 annually for the cats, and the cost of feeding my animals good meat for a year would amount to about $4,000. If I stopped feeding my beasts supermarket meat, I'd have to buy packaged animal food, and I suspect the treatment of many of the animals that yield the meat that goes into that is even worse than what's shown in those clips. I have, in other words, chosen what I think is the lesser of this particular evil, given my extremely modest income. Although, come to think of it, breaking down the costs this way is making me think I should at least switch the cats to good meat. So that's something.