I just got done growing a low yielder with a 150w HPS and I'm only expecting to get about 7 grams. My HPS made the nug really dense so that is good news, but for an indica you should expect 7-14 grams dry and with a sativa something around 10-20 grams. Hopefully you can keep a few of them going as females and get around 2-3 ounces in the end. Don't forget to let them flower for long as possible and ripen up to maximize thc and weight. The veg period also has a lot to do with yield. I only vegged my indica strain for 3 weeks and she was real small to begin with. If you have some big girls and throw them into flower, you'll be see'n a lot more bud growth.
Goood luck