First, you don't sound cruel at all. I totally understand not being able to spend money you don't have. It is also not a bad idea to liquidate birds if there are problems - just don't be one of those people who offer sick birds for sale without alerting prospective buyers of the problems.
That would be very unscrupulous.
Birds with an attitude are problematic.
There are many great birds in the world whether you want a lap pet or an independent non-human aggressive bird.
I think it is sometimes helpful to put the lives of chickens into reality perspective.
Only in the United States, 9 billion chickens a year are killed for meat and another 305 millions hens are used commercially for eggs. That means another 300 million cockerel hatchlings are killed because they aren't needed. Then, after 18 months, those hens are culled for Campbell's soup to make room for the next batch.
Globally, that means about a half trillion chickens a year.