I'm going to be a Johnny Raincloud and say that unless you really can very easily afford a horse, don't get one.
To summarize, horses are expensive. So are pastures, barns, fences, all these things are pretty darned expensive, too. So is riding equipment, so is showing, so is trailering a horse.
A suggestion: instead of getting your own horse, lease a lesson horse at a lesson barn. Ride it frequently, take care of it all day, whether it's sunny or raining or whether you want to go out with your friends or not....see if this is really something you want. Often it sounds really good, but taking care of them all the time, riding them often, it's just not for everyone.
Cost?
Ok, the gory details:
First of all, you might not wind up buying a horse that is able to go without shoes. People will tell you any horse can have his shoes removed, 'always' actually is more like 'it depends'.
Second, your horse might do ok on a plain grass pasture, or it might not. How much grazing is available on a given farm is, again, 'it depends'.
Third, your rescue horse might not need any veterinary attention after it is adopted, or it might need a lot.
Fourth, the horse could get hurt or sick, and need much more expensive veterinary care. Suggest having about 3000 dollars worth of 'emergency fund' at all times, or health insurance, or both.
Fifth, the horse might be easy to handle, or you might need to pay a trainer to teach you how to handle and ride him. Lessons: about 40 to 100 dollars a pop.
Sixth, they need to be taken care of. Every day, a couple times a day. They aren't like chickens where you can fill the feeder fuller and go away for a while. Hiring someone to take care of them while you're sick or on vacation - that's expensive too.
Seventh, if the horse gets hurt bad or becomes really sick, he needs to be trailered to a vet clinic. Owners need access to a truck and trailer that they can use any time of the night or day or weekend.
The costs here sound really manageable on the surface - 30 for a trim, 45 for a round bale, things like that.
In truth, it's very hard to say what the real costs would be. They vary so much from place to place, and based on what people think is 'necessary'. Avoiding the argument about whether that is 'right' or 'wrong' (as horse people have very strong opinions when it comes to such things), I'll just say that some horses really need more veterinary, shoeing and feeding costs than others.
I'll give an example:
Hay, grain, supplements and bedding per month per horse: 300 dollars a month or 3600 a year.
Shoeing, every six weeks: average, about 90 dollars per horse per shoeing (one has regular shoes, one has special shoes that cost more, one has no shoes and just gets trimmed). About 60 dollars a month or 720 a year.
Dentist, about 80 dollars per horse per year (or 6.6 dollars a month)
Veterinary, vaccinations in spring and fall, works out to about 120 dollars a year (or 10 a month), probably need to add more for worm medication given every 6-8 weeks.
Doing all our own work, per horse, feeding(20), cleaning stalls(30), bedding (10), filling buckets (5), turning out, bringing in (10), sweeping, etc: abt 1 hr 15 min a day, or 45 hrs a month per horse.
Figuring that most of the time that you spend on your horse is time you could be working at a job, there is a 'cost' of doing your own care, about 450 dollars a month.
That works out to about 377 dollars plus labor, or 827 dollars a month, not counting what it costs to maintain your barn, fences, and the extra property tax you pay when you build a barn on your property.
You probably need a place to ride. There might not be any connected to your property, and these days, there are not too many places where it is still safe to ride on the road, either just to ride or to get TO a place to ride.
Of course, some people keep their horse out most or all the time in a field (if they live somewhere where there is any grazing all winter), which can bring the cost down (unless you had to buy the land, LOL). They ride in the field, the horse lives in the field, maybe there is a three-sided shelter in the field, just a shed.
And some people board a horse. Board prices vary a lot. A backyard type barn, a do-your-own-stalls type barn, is cheaper. A 'full service barn' or one that has a trainer around that gives lessons, those are often more. So board can go from 300 to three times that or more. Board does not include veterinary care, shoeing, vaccinations, lessons, etc. Boarding stables usually have hours, you can't come just any time.
Plus...er...boarding at a stable can be...its own sort of ... head aches....