I can't tell from the ad if it's a good deal or not. Condition of the boat and motor matter just like buying a car.
Taking a good look at the boat inside and out will give you an indication of condition of the hull. It looks like a welded, rather than riveted hull but I'd have to see it in person to be sure. Welded hulls have less issues with leaks - but....my boat is an older riveted hull and it's leak free so rivets aren't a deal killer, just look for loose rivets if it has any. The aluminum hull is pretty simple, not a lot to go bad.
The thing I would investigate the most would be the outboard motor. Id' want to see the motor running in a tub of water (the motor needs to be in water to run as it uses the water to keep the motor cool). It should start right away if electric start, should start on the first couple of pulls if it's pull start. Run the throttle through the full range slowly and let it run for a few seconds at idle and somewhere around half throttle. Most problems are at idle - spend 10 or 20 seconds at idle and listen to how evenly it runs. Pops, sputters, or instants when it seems to go quiet are worrisome.
Compression Test: I always do one of these on a motor. You remove a spark plug and install a compression gauge instead and crank the motor. Remove all spark plug wires first so it doesn't actually start. I'm sure there are youtube videos on this. A compression test is a really good indication of how worn a motor is. The engine cylinders should be able to produce a certain pressure. If it can't do that, it's an indication of a worn motor. There are lots of other things that could go bad but a compression test gives you 80% confidence that a motor isn't simply worn out from use or damaged from being used without adequate lubrication. You can find the specific compression numbers for that motor online. Typical ranges that are good would be 90psi-120psi. Less than that is worrisome. And you want all cylinders to be within 10% of each other. I think this is an important test to do.
Water Pump: There should be a stream of cooling water coming out of the tell-tail. This tells you if the water pump (and other associated stuff) is working. If it has a temperature gauge, I'd run it for 5 minutes and watch that gauge.
Transmission: You won't be able to shift it into gear in the tub of water or you'll blow the water out of the tub. After the motor is stopped, try to turn the propeller. In Neutral it should turn freely. In Forward or reverse it should turn an 1/8 rotation or 1/16 rotation (these are really rough estimates) but should lock up and not turn after that. Back to Neutral and it should turn again.
Propeller: These are replaceable so a chipped one isn't necessarily a deal killer and most used props will have a little roughness at the edges. Bent or broken areas are bad. But props are disposable so I wouldn't reject a whole motor for the prop - but I would negotiate the price keeping replacement of the prop in mind.
Lower Unit: in Neutral spin the propeller. It should turn smoothly and not wobble at all. Push the propeller in toward the boat and out away from the boat. You might feel a tiny bit of movement but it should be small enough that you can barely see it move in and out. If you can see but not feel that movement, it's not too much. Crunchiness, grinding, loose wobble, or excessive end play are bad.
Under the Cowling: Remove the motor cover and have a look. If you really don't understand motors, you can still spot really bad, hacked-together repairs. If it looks like no factory would ever do it that way, it's probably not right. You don't want a well running motor that is going to be a future repair problem. Ask if you see something. Sometimes there's a reasonable explanation why things aren't factory new.
It's tough to know if a boat is quality without knowing much about boats. If you have a knowledgeable friend, bring her along. If not, any friend to bounce things off of or to catch things you missed might be a good idea.
Consider not buying the first boat you go see. After you've inspected a half dozen, you will know more about it. I had been on other people's boats a lot and had some small jon boats for fishing. I bought my first "real" boat a couple of years ago and didn't really know much about them. I read a lot before I went out and I'm glad I didn't buy the first one I saw. I learned a lot about what to look for by just looking at several of them.
Good luck.