There's a lot for sale during show season but they also ask more for the horse during show season compared to winter
Springgggg? It just personal preference
I would recommend getting your horse the time of year/temp. that they came from (if coming from somewhere with a different climate) If that is not necessary for your horse then get them whenever you have the right supplies (for winter - blankets, heaters, etc) or whenever you're ready!!
Fall to winter, or mostly all year around, because when it goes into winter they don't have the needs in the cold to keep their horse healthy
Hi Julia, a lot of people tend to try to sell their horses during the winter circuits (WEF, HITS) because a lot of people are there and it's convienent. That way also the new riders have a chance to get used to the horse before summer shows too!