I currently have a growing population of N. zhangjiajiensis (wild-color snowball shrimp) in a 30 long, as well as cherry shrimp in a 10. My lfs doesn't deal with shrimp, so I sell them online and ship them. I started with 15 cherry shrimp in the 10 gallon less than a year ago, and have sold hundreds of them since then. I don't doubt the other shrimp will be as easy to sell, I'm just waiting for their numbers to increase first. They do produce larger broods than cherry shrimp, and seem to grow faster as well.
Some of the profit from the cherry shrimp went into the 30 (tank, stand, hood/light, etc. at a yard sale, $50 for the whole setup) and some dwarf crayfish from Germany. Along with the crayfish, I also received a few of the wild-color snowball shrimp.
It took them a couple months to start breeding, but the first broods of young are now nearly breeding size. I should have a great breeding stock soon, and will be listing them f/s as well as more of the cherry shrimp.
Then there's the dwarf crayfish, the only bad thing is they don't breed nearly as fast or as often as the shrimp. However, considering the demand is much greater than the available supply, they should be worthwhile in the long run.
The ironic thing is, after years of keeping/breeding fish, the shrimp are the only thing that have ever actually paid for themselves, much less been profitable.