First off, I think that's a good question on your part and shows that you are really thinking this out.
I just got a horse a couple weeks ago (after not having had horses for over 10 years), and I had to budget, plan, and think this out for about 6 months before I made my mind up. Writing up anticipated costs and just researching and talking to people really helped me. I called my vet a lot (I'm lucky that my vet sees small pets, equine, and bovine) to ask questions. I asked horse-owners in my area questions. I wrote down figures over and over to get an idea of annual cost (and came up with different answers every time :). When I was sure that I could afford it and had back-up "emergency" money, I went for it.
Yes, the economy has affected me like everyone else. However, rather than make cuts in my pets' expense needs, I've simply made some cuts in my personal budget (shopping, going out to eat...). I think it's worth it to keep my babies, because they make me happy. :) It's all about prioritizing, but definitely keep planning like you are.