The economy is horrible right now, but it is, actually, a business for a lot of people- my neighbor does that, actually! He buys horses for almost free off the reservation, then trains them (he's a very good trainer, too) and sells them for a lot more... or he used to get a lot more, not now. He's not been able to do as much lately... But still, there are people who do this for most of their living.
I think in the right hands, this is a good business.