Sure I had my losses but certainly not from diseases. Mostly from shipping stresses but I really never lost more than 5 at the most out of 25 chicks.
Yes if you want show quality or chicks that may have BQ or SQ, buy them from a breeder that is showing up to standards, not a hatchery. It is a very very small number of chicks that would even be close to SQ.
Often hatcheries would buy out a breeder's flock when the breeder wants to get out of raising that specific breed OR retiring from poultry world. As soon as you know who and where the flock went to, better get down and get them in the first year they offer otherwise, in the second and third year, the chicks would not be of good quality anymore. They don't cull as hard as real breeders do, getting down to the nitty gritty of the standard, picking their birds apart and what they can work with such a very small flaw or fault that could be bred out.
I am sure many of them will be more than glad to help you out.