You need a better class of client then! The persona you're describing are the intended audience of premium themes. They would probably never really get anywhere

You need a better class of client then! The persona you're describing are the intended audience of premium themes. They would probably never really get anywhere with their "new idea", if the barrier to entry was higher than $39 or $2 hosting a month. May I suggest hooking up with a larger agency, or corporate entity to help weed out the worst for you?