I searched YW and found 11 Hunter 27s. None of them were listed in Middle River though. Where is your broker located? Where is the boat located? That has a lot to do with people buying a boat if they don't want to bother with a long move, and for a boat of this size and price point that is a major factor.
As long as your boat is on the site and pulls up when you search Hunter 27 or pulls up when you search for a used sailboat, length criteria that includes 27 feet, price range and other criteria that describes your boat I am not sure where it shows up on the list is that important. As far as Hunter 27s are concerned, there are only 11. It's not like "google search" where people will probably click on the first few that show up. Used sailboat buyers will most likely view all that match their search once they get it narrowed down to a price point. Most used boat buyers, once they have said, "those 198X to 191X Hunter 27s look like a candidate for me" will narrow their search and your boat will show up in a smaller list. They will then scan the whole list. What you need to do is make sure the pictures are great (if the boat is okay), not just okay, and the description is snappy (but truthful), and the price you have placed is realistic or even better, a price a buyer will focus in on in the search. Just my opinion of course and worth only that.