We live in a pretty expensive area. Full board is about $350-650. I've seen it cheaper at private farms for partial care, as low as $175. We do not board, hay is $4 a bale. Grain is between $11-15 a bag. Our fat horses only get a cup once day with their supplements so it lasts us months.
-Farrier $90 for front shoes, I think $130 for all around and $45 for a trim, more if you need bar shoes/pads. Our farrier is one of the cheapest in the area, I know more than one farrier around here that chrages $200+ for full shoes.
-Vet- I can't even begin to decifer his handwriting to tell which shots were for the horse and which were for the goats, but prob was around $100 a horse including cogins and call charge for spring shots. He is also one of the cheaper vets in the area.
- Floating $100 a horse. A bit more if you need a tooth pulled, but he's very reasonable
-Dewormer is usually $7-13 a tube
The vet check is going to depend on what you want done. You will probably have to pay a call fee, our vet charges $45 for that. Then the price is going to depend on if you just want them to look them over, check joints etc, or if you are going to want x-rays done.
Tack is going to depend on what deals you find. You can usually pick up used halters, bridles, girth, pads for really cheap. The saddle is probably whats going to get you if you want something that is quality.
I agree that you should have an extra "cushion" for emergencies. I blew over $1600 on a mare that I had just bought a month prior. And of course it was when work was really slow and I only had $600 in my bank account. I ended up ebaying off my saddle and all my tack to pay for the bill. In hindsight I think I should have just ebayed the horse and kept the saddle