i generally start that conversation with---" a queen sized quilt starts at $500 and goes up from there, what did you have in mind?"
that usually makes them leave me alone
unless they seriously do want a quilt-
sometimes i say- sorry but you can not afford to pay me to make you a quilt---then i make them one as a gift
it depends on who it is- but non-quilters really have no idea what goes into making quilts and think they should be able to get one for the same as if they went to Walmart & bought one-
sometimes when they get my (token answer) of $500+ they start to ask questions- and we can actually discuss a serious answer-
this answer also works for the people i have no interest in making a quilt for- - i've been known to double that response if it was a quilt i hated making in the first place- i never make the same quilt twice- not one time since 1976 have i made 2 of the same quilt- the only options i give when someone wants to commission a quilt is- size, color scheme, theme---beyond that it is up to me...this works for me- i stay busy and sell enough quilts to 'support my quilting habit'