I'm probably not gonna breed them until September (unless I just can't wait, lol) as I'll probably be working full time in summer, than vacation at end of August. So hopefully by then they'll be ready. How much should I sell the fry for? And at what age?
This is basic breeder "stuff" you should already know. If you are planning on breeding there is way more than putting two fish together and getting some money off of them. Even if your intentions are not for profit.
Please research this and then decide if you want t breed for sure or not. There are a few "Sticky" threads at the top of this section and they say betta breeding or something like that. Please read and go through that to have some kind of background. You really need to research before breeding ANY kind of fish or animal for that matter.
To answer your questions, it really depends on the quality of the fish and what tail type it is.
Usually around 2.5-3 inches is the correct size to start selling them because they will have developed their color and finnage. The price is really your decision. If you look on
www.aquabid.com, you should see fish similar that have prices according to their quality.
Breeding takes time and money. You need at LEAST 50 containers to separate the males and a grow out tanks at least 30 gallons or more.