Personally I wouldn't make one for less than $150. My time is actually worth something. Even every day mundane tasks if you had to pay someone to have them done would cost at least $10 an hour and I think housekeepers have gone up to $15 an hour in most places. Every second I spend working on something for somebody else is time I'm not spending on my own tasks.
And quilt making is NOT unskilled labor!!! Just because you do it for a hobby or your own personal pleasure does not mean that you should have to do it for pennies an hour for somebody else.
When you get paid for a quilt you are in business, even if it's just once, it's still a business transaction.