How much roughly do already started plants cost?

they are more expensive than seed, but worth it in my opinion, especially for beginners I'm not sure if you can buy green beans in a starter plant. but $10.00 should cover everything. make sure you get strong healthy plants. if you buy some that as been t inside you will need to leave them outside for a couple of days before you plant them, so that they will be used to the temp. change.