What might also help is setting the price range. It might help weed out all the extremely cheap options and some of those ads with variations that start at a super low price. You can also elect to search at Australia only listings.

As for feedback, just a question. What is your purpose when you give it? If it is to help as a guide to future buyers, then a comment of Z is useless. 

If it is to give the seller some idea of whether things went well or not, a comment of Z is also useless.