Bean Sprouts at a farmer's market is probably not going to be a huge seller. Although, I've never tried selling them, I have grown them. You soak them, put them in the dark and then rinse them twice a day until they sprout, then you have to rinse off the hulls. It's really quite a labor intensive and since they're in the dark (out of sight, out of mind) they tend to be forgotten. I think there is also the worry of bacteria growing.

I'd say unless you have a huge Asian population at your market, or someone happens by that is making pad thai that night, you'll be going home with them.

You should search "micro-greens" on this forum (similar type item). There is a very good thread on micro greens.

Google and find some sites where commercial bean sprouters are sold. That will give you a better idea of the process. Because of some e. coli outbreaks involving bean srouts some states classify it as a processed food requiring health department regulation. Tom