Few years ago, but 3K for the pony, about 1K on tack, then 3K a year livery, monthly insurance, treats, replacing ripped rugs, fly masks, halters and lead ropes, probably at least £100 a month, 6 weekly farrier shoes on the front and a back trim £50, Vet bills not very much as he was a tough little blighter, but potentially the skys the limit.
Then there is gear for the rider, boots, jods, hats, gloves, socks, thermals for winter, riding jackets, for the yard and hacking out. Then you might want to get into showing, so show jacket, breeches, boots, shirt and hat, not to mention you might get to the level that needs a dressage or jumping saddle and tack. Or both.
Keeping clean stuff, for the horse and the tack, grooming aids, grooming kit, fly spray, worming meds. Lessons, clinics, fees and travel to shows.
If I hadn't had a pony and saved the money instead, I could have retired probably 5 years earlier. But, I still don't begrudge or regret it.
Oh, and then there is the injuries to the rider, broken finger, broken wrist, broken ribs, broken collar bone, black eyes, horse fly bites, huge bruise from a horse biting me, (not mine) and squashed toes that are now a permanent funny shape.