A Grand Mariner--- and I assume you're looking at Scout up in Nanaimo--- was made in Taiwan and is just one of many marketing names that were applied to a number of almost identical boats that most likely came out of the same set of basic molds and were finished by small family boatyards. Some of the other brands that came from these same molds are Marine Trader, Puget Trawler, La Paz, Chung Hwa, CHB, North Sea Trawler, and C&L.
There is a very informative article about these so-called "Taiwan Trawlers" that was published in Passagemaker magazine. It is from this article that I got the information above. The URL to read this article is
http://www.bluehorizonsailing.net/wp-content/uploads/2012/02/venerable_taiwanese_trawlers.pdf
Hopefully that link will work for you. The article is about this whole type of boat in general, not Grand Mariner specifically. But it should give you a very good idea on what to look for in this generation of Taiwan boat.
From the ad, Scout looks to be very well equipped with some nice features like the SeaWise davit for the dinghy on the stern. But pictures and descriptions can be very deceiving. If you decide you are really interested in this boat, a survey but a topnotch surveyor very familiar with these Taiwan-built boats and the problems they can have is a must. The good news is that good surveyors are probably pretty easy to find in the Nanaimo area.