You can get much more than 10g per plant. I averaged 1.5-2 oz (dry) per plant 12/12 from seed. 4x4 tent with LED and promix. First few plants were closer to 1/2oz, but once I got things figured out it worked very well.
They'll start showing sex around 2-4 weeks, and then normal flowering time from then on. Worth it if you are low on space, or have decent numbers to work with
It can become a bit of a pain with many different strains at different stages of development, and you'll go through a ton of seeds. Good idea to have somewhere to keep mothers and root clones in case you find something you want to keep around. When I started off I just kept them in the same 4x4, and took them out a few hours before lights on and let them get light from one of my windows to keep them vegging.
Don't be put off by hearing 10g per plant or less. That is just not true unless you do something wrong or your setup/nutes are not good enough. Start a couple seeds every couple weeks if you want perpetual harvest.