Autos are the easiest to grow for beginners.
You mentioned wanting quantity cheap. There's another variable for you to decide, time.
Do you want the fattest cheapest buds possible or the fattest cheapest buds in a hurry?
If you are in a hurry like me here's a good way to wring-out your auto.
Decide on a cheap light and let it get good and warmed up. Hold your hand under the light at various distances from the light.
You want to determine how close to your meager light you can put your baby without her getting burned by the light. This is
critically important because the only way to make for low light is to get as close as possible to the sucker. A plant 4 feet from the light
gets 1/4 as much light energy as one 2 feet away.
After figuring out how close to the light you can get you have an idea of how tall your finished plant can be without burning. Now you
need the right pot. General rule is that a 3-gallon pot is fine for keeping a plant 3 months. Your auto will finish somewhere from 8-12 weeks.
That would suggest a 2-gallon pot usually, but you will want to go smaller. I would suggest 6 or 7-quart containers. You want your auto to
have a full rootball and that happens when the roots are long enough to reach the sides of the pot. The sooner the roots hit the sides the
sooner it will start to grow up. So the roots will fill the small pot soon and then grow green. A 2-month plant that has been in a one gallon pot
will be larger than a 2-month plant that has been in a 10-gallon pot. So, fast = small pots.
Leave the light at 20/4 and kick back. That is the light cycle that produces the most and fastest growth in autos. Autos don't veg, you know, they
go straight from seedling to flowering stage. Kinda like my cousin.
Holler if you have any more questions. Better yet throw me a PM and I'll get back to you.
BigSteve.