This is an interesting thread. It’s a ways from my background, but here’s my take on it.
OP, you may be best leasing a horse at a good facility that you enjoy.
I have been very fortunate to be born into a horsey family, and have always had horses in my life, for the last 60 years (scary). But I’ve never bought or been bought a “made” horse, a “fully trained” horse, or an expensive horse. Always young horses, green horses, or repurposed horses. We have always kept horses at home, the few times I’ve boarded out a horse, I have been disappointed. I have ridden h/j in competition, all levels. I’ve owned and trained and been involved in the TB racing industry for several decades.
All I can say, is that when you are buying a horse, it’s much like buying a lottery ticket. The only difference being your skill and experience in making your selection of which lottery ticket you buy. You do not know whether this purchase will pay off, and there are many hurdles in front of you to make it pay off. Even if you buy a horse who is fully trained, with a “show record”, and passes a pre-purchase exam to calm your nerves… there are NO GUARANTEES. If you can’t accept this, or can’t afford this, don’t buy a horse.
This is the difference between a “horseman”, and someone who buys a horse. A horseman knows, in advance, that problems and issues are going to come up with the horse, and that the horse may not be what you want it to be, and accepts this, NO MATTER WHAT $$$$$$$$$ YOU HAVE PAID FOR IT. If you are rich, and money doesn’t matter to you, you may purchase any horse you like, at any price, and perhaps this will work out well, and if it doesn’t , it doesn’t matter. If you are not this person, you need to pay less $$$ when you make your purchase. And becoming an actual “horseman” yourself, in the acquisition of skills and experience is worth a lot of money. So the horse you buy gains you experience, and skills, whether or not it turns out to be the horse of your dreams. So it’s still a valuable experience, to a horseman. The money you pay is tuition at the school of horsemanship.
If you enjoy the lifestyle, it is cheaper to keep your horse at home. Horse are often healthier, and sounder, if kept and cared for in a “non-industrial” context. Lots of turn out, not in a jail cell with bars on the windows, fully clipped and blanketed. If you enjoy the “high class stable” look, crystal chandeliers, brass fittings, and a name plate on the stall door with the horse peering through the bars of the oak stable… there will be expenses associated with this plan. Expenses and health issues for the horse. Any lifestyle does have risks for the horse’s health and life. If you own one, you must choose and accept the risks involved in the choices you make with how you keep your horse. We have always chosen the first option, not the fancy show barn but as much turn out and socialization, as much as we can, depending on our location (which has changed through the decades). The longer you spend owning, training, riding, and caring for horses, and the more time you spend with skilled practitioners, riders, trainers, coaches, vets, farriers, the more you can learn to do for yourself, if you care to. The more you can do for yourself, the more affordable it all gets.
Good luck in your search for a horse owning/riding situation. These days, it’s about the only thing that is worth pursuing, IMO.