For money? First and foremost choose species that you know you can sell. Ball python morphs are in highest demand right now. Albinos and pastels are some of the least expensive. Albinos (and all the morphs) will eventually be sold for only a few hundred dollars and less. But even at only $300 each, an average ball python clutch of 6 will bring in $1800- well worth the effort.
Corn snakes continue to be in demand (and I personally intend on producing these large scale in the near future - albinos, miami and hypo miami, patternless). However, one would have to work with more breeders to see a sizable return. However, they are SO easy to keep and breed and hatch out! They are so easy to work with (great feeders, moderate temps, little space, quick to breed, eggs easy to hatch)! One could literally maintain 400 adult breeder corns in a 10' by 10' room if properly designed.
If you plan on large scale, start breeding rodents now and devise a highly efficient operation... TRUST ME.