I see a ton of interesting used motorcycles available on Kijiji ( a free online Canada Classified ads site ) there are so many large displacement bikes available at similar prices to this ( in canadian $ ) I have to wonder if it’s not because the cost to insure these rides, has pushed them out of reach for so many long term owners.
The Yamaha 750 triple was reputed to have some ‘issues’ with carburation, ignition and exhaust pipes, so if that XS does not run as is, I would keep looking. Besides 750 triple is a lot of bike to learn on and since you are considering a machine of that vintage, there are many machines that have since disappeared from the market, including 350, 450 and 550 cc offerings.
…Not to say that one is not a great deal, because as Jeff said, I would need to see and hopefully hear it to pass comment.