The importance of environment when purchasing a horse
I have looked after horses for almost 20 years. In that time I have kept my herd in two places, county Kildare and West Cork. My herd consists of two Cobs, a Thoroughbred and an Arab pony cross. The Thoroughbred and the Arab thrive in Kildare, while the cobs thrive in West Cork.
In Kildare the grass is rich rye grasses, the weather is mild and the winters are not too long.
West cork is the opposite, lower grass quality and long, wet miserable winters.
It is important to factor in where you are going to keep your horse and if that environment is suitable for the animal. Consider breed, type and good/poor doer. The cobs do well in West Cork as they are built for the climate. In the rich plains of Kildare, they get over weight very quickly which leads me to pen them on concrete with hay. And that is not a situation they enjoy. They become so unhappy, which impacts their welfare.
While on the other hand, the Thoroughbred and the Arab thrive there as they need lots of calories and would be considered poor doers. The weather is nicer on them and their three F's are always met (forage, friends and freedom).
So when you go to buy your next horse, think about how the animal will respond in the environment you have have available for it.