Transportation (something cheap $1-2k)
Not long ago we would have put the horse in that category...and that's what we are really talking about - the horse.
I happen to be of the opinion that once you have an animal you have a moral/ethical obligation to care for it for the rest of it's life. At that point its needs become your needs.
I don't think you NEED a horse. But now that you have one, its needs are needs to you.
It so happens that horses are expensive and they can be sold so maybe there is a difference from a pet like a dog or cat.
I grew up in a rural area. I know that back then what some people sometimes did, especially when they went off to college or if they could not afford their horse, was that they "loaned" them to someone else on a semi long term basis. The person they loaned them to would have full use in exchange for feeding and caring for the horse. Usually it was for a fairly long period like a year or two. Actually, I know a woman now who is taking care of two horses right now in a similar arrangement so that kind of thing is still done.
I'm not sure if that is an option for you but it might be something to consider.