I'm not sure where you're located but here they range from $5-$15. We couldn't sell ours as it was early summer so we dressed him at 18 weeks. We could've waited until 20, but I think he was beginning to get stringy so I wouldn't go over that next time. We roasted him, and it was great, but due to the early stringiness, I'd suggest chicken and dumplins, gumbo, coq au vin or the like.
What is most important, it the temperature. And temperature spike, and the meat gets tough. LOW temps. Even when turning a chicken into soup, if you let it boil, then the meat will be stringy and chewy. You need a very low simmer.
The difference is that all that chicken at the grocery store is baby age... Anything from our backyards is much older, so LOW temps!!!!!