You'll need some sort of permanent fencing, electric tape/rope/wire alone in not sufficient for permanent housing.
To properly keep a horse, you're looking at WAY more than $1,000/year. You can easily spend $1,000/year on farrier fees alone.
A horse should definitely not be kept alone. they are herd animals, and should not be kept in isolation. I wouldn't recommend a goat, a goat is not another horse and will not replace one. They can male good travel buddies for horses that otherwise have contact with other horses, but should not be sole companions. Some horses also kill goats.
Likewise, whether a mini will work depends on your horse's temperament. You can't just chuck any two horses into a field together, they have likes and dislikes just like humans. Some horses can and will kill or injure a mini either on purpose or accidentally.
Tack cost varies substantially based on discipline, quality, and purpose.
The age of the horse depends quite a lot on your intent and skill level. And is far from the only factor. Some 20 year old horses are for advanced riders only, while some fairly young horses are good for less skilled riders.
You don't necessarily need a barn but having an area where the horse can be restrained and taken inside for vet care, extreme weather etc is a very good idea.
I would NOT be buying a horse off the internet or anywhere else right now. Your questions raise a lot of red flags that indicate you are not ready for a horse yet. I would advise continuing on at your lesson barn, and taking advanced classes in horse care there as well- learn about feeds, tack type, how to choose the right bit for your horse, how to recognize and respond to common medical situations etc. There are also hundreds of great books and magazines that can help further your learning. If one day you are ready, and financially able, to care for a horse of your own, your first horse should be bought with HEAVY input from your riding instructor, they should view horses with you, and you should give them veto power. Many instructors will actually help find a horse to suit your level in addition to viewing horses you've selected to look at. Horse buying is a serious prospect with many considerations- it is very easy for a first time buyer to end up with an unsound or temperamentally unsuitable horse through shear inexperience.
Edited by nebit, 05 April 2018 - 04:29 PM.