I agree, with others, from show quality lines you could have show quality birds, breeder quality birds, and pet quality birds. Birds could hatch with a flaw in color pattern or a comb that isn't perfect or other flaw (or recessive trait) that does not meet the SOP for some reason. Keeping this in mind, if you wait until the birds are older to sell them, it will be more apparent which ones are truly show quality and you will be able to charge more for them. The downside is that by this point you may have spent considerable resources raising others from the same hatch that cannot fetch as high a price. It may be nice to sell at different stages of development for different prices. You could sell day old straight run chicks at a relatively low price and the buyer would be taking a gamble on how well they will show, you could sell others at a few weeks old where sex is more obvious and any flaws may be a bit more obvious at a slightly higher price (in particular I think of those in 4H that are just getting into showing where actually raising the bird is an important part of the process), and then you can have older birds still that sell at an even higher price if they are the best example of the SOP (a big advantage of this is that you can keep the best for your future breeder stock at this point). Just some things to think about. Hopefully others that breed for show can advise if selling at a certain age is more advisable/profitable than others.