My Gracie,
Sorry I should have clarified. I did not breed Arizen. She is still owned by my trainer right now. My trainer is breeding her until I graduate college and I'll own her in October 2009 when baby #2 is weaned. My trainer is an experienced breeder and bred her along with all her other premium mares. I would not have chosen to breed her at this point. If I did, I'd send her back to my trainer to breed her because even though I've been helping with the breeding and learning a ton, I still wouldn't feel comfortable doing it on my own.
I don't know the exact individual costs of what she spent on breeding her foals, but I know that each foal cost about $3,000. And she does the insemination herself and all the basic vet care for the mares. I think that the cost includes the feeding and care for the mares along with the equipment she needed for the breeding (insemination equipment, test tubes, etc.). She owned the stallion and the mares, so she did not have to pay a stud fee, obviously, though it may have been taken into account when determining the cost of the babies.
Things that went wrong this year: One mare got an infection from how bad she got ripped up from the foaling since it was her first baby (and a VERY large one), A few mares weren't producing the right nutrient levels in their milk and the babies had to be hand fed from another mare's milk until the nutrient levels changed, One mare's motherly instincts weren't very strong and we had to encourage her in the right way so that she wouldn't reject the baby.
All these things cost money and take experience to handle. Not to mention the efforts we went through to make sure the babies' legs stayed straight and sound (wrapping, dealing with injuries, feet trimming, etc.).
But she's a breeder. Lets say you're not a professional breeder, like in the instance of the OP. You're looking at stud fees (which if you're breeding for quality will be $800+ and may also require a booking fee of approx $200), vet fees for the insemination and ultrasounds or checkups, dont forget to up your feed bill because the mare is eating for two now, then if you take my advice and board her at a breeder's facility we all know how ridiculous board rates can be, and then if something goes wrong... its a LOT of money.
But like I said, if money isn't an issue, then the only reason not to breed is because there are already thousands of great foals out there looking for homes for very reasonable prices, which I believe is a good enough reason not to breed in the first place.
Hope that clarified my position a little. :)