I guess i don't see it... i don't know of anyone that posts something for sale and doesn't know what they want for it. How hard is it to just put a price there?
I have never seen people get so upset about someone suggesting "for sale" items should be priced. Why waste everyones time by e-mailing or calling to find out it's more than you want to spend or it's sold?
I don't think it should be a "rule" but just be curtice to other guys/gals here.