Fren, it really is worth it.

Noise = 0/5
Space = 1/5. A tiny garden is enough.
Smell = 1/5. Clean every two days and you'll be fine.
Money = 15 bucks for food / monthly
Attention = 0/5. I literally just go there in the morning to check they are ok. In the afternoon to pick up eggs. Once / 48 hours to clean their pen. In fact I think they couldn't care less to not see me, their egg production doesn't change if I'm around or not.

If you have dogs, don't let them stress the quails or their production will lower.

But man, if noise, smell, attention or money are your concerns, then Quails are for you.