I don't know what its like in the states but here in Canada your supposed to claim all of your earnings on your income taxes including assets that you sell (this includes garage sales!!). People don't - but thats the reason why I don't recommend that hobby breeders advertise themselves LOL. Unless you want to register as a breeder/ obtain a small business licence and be upfront about it - and give the government all of your money (boo!)..
Just my two cents - I also don't know the laws in your region so don't quote me![]()