A few that come to my mind are :
Mojaves
Fires
Albinos
Bumblebees
possibly a pied male (I've seen some as low as $825..kinda depressing though to see them priced that low)
spiders (with some size on them in price range)
Ghosts (hypomelanistic)
Lessers/Butters
Pinsripes
Spotnose
etc....
Since you are new to ball pythons I'd recommend slowing down on the breeding thoughts. A lot of work and money goes into this (I don't mean to attack you, so please don't take offense)
However, starting with babies and growing then up 2-3 years will teach you a lot, which is what I'd suggest![]()