It's better to attach your log file where could give more details why you saw the warning "No content found for Price", is it possible that specific detail page don't have the price element really? you also can try to mark check "wait for element" option for "Price" element in Misc tab, see if it works for you?
the log file can be found in default log folder. e.g,
- My Documents\Visual Web Ripper\Log\[project_name]_info.log
if you cannot figure out the cause, please attach the log file at here, thanks.