Something to think about is how much feed are you going to put into those 20 birds to get them up to butcher size and how long you will be housing them. If you did it on a large scale like some of the big farms out there, you might make profit but otherwise the way you plan to do it with 25 day old chicks, then raise them up and hope they all live, put too much feed into them, and hope you can find a good butcher that will do them and is able to sell them to the public (meaning it will cost some $ to get them butchered/packaged), and that is not to mention that the 5 you plan to keep actually turn out to be the gender you're after.
If you just want some goldens, look anywhere online and you can find a pair or trio for much much cheaper than what you're planning to do