You should start by checking all animal shelters in your area for horses up for adoption. This will cost you much less than buying a horse from a rancher and it will give a homeless horse a home. Start with your local SPCA.
I know someone who bought an absolutely beautiful horse that was a retired racehorse -- they "retire" very young. If you can find someone who deals in racehorses, you might be able to get an excellent price on a young, very well-bred & gorgeous horse. :)
I found some good ones on horseclicks.com and equinenow.com. Where do you live? I can reference you to a good breeder if you have the $ for it. :) be careful, some cheap horses come with a lot of problems