There is cheap discus and there is quality discus.
Head over to http://forum.simplydiscus.com/
to learn how to pick a good discus before you buy.
I second these comments.
The simply discus forum has a number of top-notch discus supplier sponsors who are long-term, highly reputable suppliers of high quality discus, and Hans Discus in Baltimore, Md. mentioned earlier, is one of those.
He is without question the best place to get healthy discus for anyone living anywhere in the north-eastern U.S. states.
And in my experience as a discus-keeper for many years, starting off with top quality, healthy discus is 50% of the way to being successful keeping discus !
That doesn't mean that you can't get good quality discus from the many local hobbyist breeders in many states, but you need to be in the market for small young or very juvenile discus if you buy from a breeder, very few of whom will sell anything over 2" to 2.5" in size.
And the problem with getting young fish like that is they require a significant amount of extra care & attention by way of large daily water changes, multiple daily feedings, and bare-bottom tanks ,to grow them out properly without stunting them, or losing them to a variety of pathogens, given their under-developed immune systems. Growing out young discus obtained from hobbyist breeders is only for the well-experienced discus-keeper, not the novice to discus-keeping.