We have a small flock of seramas. Not kept for sales or show. Just spoiled pets and we like to hatch. Serama eggs can be tricky or can hatch with ease. Using a good incubator or bantam broody increases your chances of a good hatch. Size Bs breed, lay, and hatch easily. Size As can sometimes have poor results..... but people go crazy for "tiny." There's also some with a short legged gene (like the Japanese) which can cause death in shell if bred to another short legged serama. If eggs develop but several die in shell, it could be a genetic issue. Just something to be aware of when selecting breeders.
You can line breed chickens but best to avoid first degree relatives - like siblings. Better to use birds not that closely related. Line breeding is a carefully selected kind of inbreeding that can increase desirable traits but can also make genetic defects more prevalent.
I have made a few mistakes. One was selling day old chicks. I wish someone had warned me that Serama chicks are more delicate (like quail). They are extremely sensitive and that 1st week can be challenging. I sold 2 to a lady who already raised chicks and was familiar with chickens. Her family was very excited and wanted to bond with chicks right away. I called the family about 24 hours after hatch. I saw the chicks eating, drinking, and running around the brooder. Appeared healthy, with no herniated navel or other concerns. That afternoon the chicks were picked up. By 9pm both chicks were dead. Kids were very sad. I felt terrible.
Since then I never sell seramas under 1 week old. (Other LF breeds like my Orpingtons - not a problem) Even when raised here, I have seen a serama appear OK at hatch, but fail to grow. If a chick is not growing at the same rate as its siblings (even if eating/drinking/acting normal), it should not be sold. Sometimes with TLC and special care, a runt may pull through; other times there's nothing that helps.
Prices are all over the place. Right now in our area on Craigslist I see a woman selling young cockerels for $75-150 and pullets for $50-75. I see another person selling 2-4 week old seramas for $5 each. A 3rd person is trying to give away a serama cockerel.
The general demand at any given time fluctuates. Some times I sold out in a day and had a waiting list for my next hatch. One time I had 10 serama chicks for a month with almost no interest.
The males are wonderful to their hens. I rarely get feather damage from over-mating - even when I have one male with just 2 females. I really enjoy how much personality, curiosity, and intelligence these seramas have. The strange jungle noises are also fun. Some males like to crow a lot, but it's squeaky, high-pitched, and doesn't travel miles away.