For the domain $6-10 Depending on the buyer. The themes are not great therfore I think people would not be willing to pay much for ownership for the themes maybe about $15-25 for them all. So a total range of $21-35 Depending on the buyer in my mind. Also the buyer would have to know how to make Wordpress themes therefore limiting you target audiance for sales.
Maybe around 50 dollars. But how much do you make from your themes? Thats really going to be the key to your sites value. if you make 70 dollars a year off those themes you're sites obviously going to be worth more money. As a general rule on sites which make money like you're you'd want to sell for three times what you make yearly.
