Welcome to the forum.
Agree with tiger79. Teak decks and original sails and rigging are top of the list of question marks. The teak is glued on and it may be just thin teak on a ply backing which Bavaria used on some models at that time. Look for the usual signs of excess wear and caulking becoming detached, or lifting from the deck. You will find several threads on here about renovating and/or replacing teak decks. No solutions are easy or cheap. On the other hand if it is sound you may well get several more years service out of it. You can't really tell much about the standing rigging by observation, but chances are your insurer will want it replaced or at least a mast down inspection. Sails are a bit easier to inspect, but the originals were very basic and tend to go baggy, particularly if it has a furling mainsail.
Engine is I expect an MD22 so pretty straightforward. All you can really do is a visual inspection for signs of leaks. Same with saildrive, but for both the service record is what is important, with evidence that the saildrive diaphragm has been replaced at least once. The original cooker was a Techimpex and these suffer from corrosion and are very difficult to service as the burners are very difficult to remove. However, if it has only been lightly used it may well be OK. The factory gas system is poor and does not meet current regulations. Electrics are generally OK, but original wire is not tinned so corrosion, particularly at terminals is a possibility.
Structurally it is worth lifting all the floorboards and looking for any signs of distortion or damage around the top hat ribs that make up the grid, particularly at the rear, aft of the keel. The bilges should be dry and keel stud nuts and backing plates clean. Look for any signs of water ingress from windows, hatches and portlights. At that period Bavaria were using Lewmar, Gebo and Rutgerson for windows and hatches. Check all doors open and close properly.
The model itself was one of Bavaria's big success stories and sold in large numbers, particularly to the Med charter market with the layout that had an extra cabin forward. I chartered one in 2000 and was really impressed with it. I subsequently bought a similar 37 for charter work. Both models were well regarded by operators as being tough and reliable and by clients as comfortable and easy to sail.
Good luck with your viewing. I am sure after looking at 50 boats you have acquired a feel for whether a boat is right. What is good about Bavarias is that they are straightforward and relatively simple. Because of the numbers made there is lots of expertise around such as on this forum, parts are mostly easy to source and replace and they perform in the way expected.
PS Is the boat called Joy, listed by Clipper? If, so, looks promising based on the details. Not messed about like some 20 year old boats. Bit surprised by the seemingly low asking price given all the good gear.
