As to your first question, it would depend upon the weight and size of the females. I've yet to get a female up to breeding size in 18 months, though I guess it could be done.
I would wait until the male is at least around 800 grams, better to be over 1000 grams. Again, you need to take the appearance and overall size of the male into consideration. Is he producing sperm plugs? Is he a good eater? Etc.
Projected profits? Don't count your snakes before they are hatched! There is no consistency in how many eggs of what sex of what morph will come out of a given clutch. You just take what you can get and hope that the odds gods were kind to you.