Why are AB Yachts so cheap on the used boat market ?

Fairenuff, if you call it "overall experience" I understand/accept it.
Personally, I wouldn't call that "driving", when what you are saying doesn't even involve being the helmsman.
As a non-mother tongue EN speaker, I'm far from pretending to teach semantic, anyway!

Why/where? Because I wrote "you're having a laugh"?
I wasn't aware that such expression (which I often use colloquially) can come across as making fun of someone, but if it does I apologize with him, because it certainly wasn't my intention.

Regardless, it's sort of funny that you felt the need to object to that PDQ, on his behalf.
Even if I never met CJ, I'm pretty sure his skin is more than thick enough to defend himself, whenever he feels like it...

Why do you just assume things of other people? The 27' Fountain (in the picture) was a slow boat, my fishing boat will smoke that thing, try riding on a 47' Fountain with triples and herring propellers.......one of my customers has one.

I find whipping a 62' Predator around the tight turns in the Intracoastal waterway at 30 knots to be thrilling. It's a different experience and the 62' Predator will turn in 2 boat lengths. So will a 40' Cabo zues at 30 knots.....that's thrilling. Whipping a big SF around the ICW turns between GA and NC is exciting. Driving anything in a straight line is not thrilling unless we're talking a 1/4 mile drag strip at a time and a car.

That being said, I happen to own a boat just like you mention. a 20' Lake & Bay flats boat with a 250hp SHO Yamaha, 10" Bob's hydraulic jackplate, and yes it is thrilling but also doesn't have any ill handling traits. Have also done 116 mph in a 20' ranger bass boat with nitrous, it was not thrilling.......just hold on and try to keep your cheeks from flying off.

My fishing boat is just like these, and yes I use it just to fish. Your imagination might run wild on some of the other speed boats I've owned. A GOOD HULL doesn't need to be driven constantly at fast speeds, see the first video. The faster you run my boat the better it rides and straighter it goes:

Lake and bay key largo 2 Mercury 300r cruise - YouTube

85mph Flats boat at River Ranch Scream n Fly 2011 - YouTube

20 ft Lake and Bay Boca Grande with mercury 250xs going 85mph - YouTube

90MPH + NO HANDS!!! 20ft LAKE AND BAY BOCA GRANDE FLATS BOAT WITH MERCURY RACING 300XS - YouTube

Actually jets are very good at high speed uTurns as they just slide around.

Simple, because that's exactly what you started doing with myself:
"You haven't driven the right 80'ers then"
Eice primum trabem de oculo tuo...

Back to the point, OK, so you did try some real speed on the water.
And you maintain that a 62' Predator can provide a thrilling driving experience.
Fairenuff.
I maintain that Predators are laughable when it comes to driving experience, no matter how hard they tried to sell them for what they aren't in James Bond movies.
It would be a boring world if we were all thinking along the same lines, wouldn't it?

I'm sure you will enjoy Rome.
Since from Viareggio you will not be far from Florence, you wouldn't regret spending a bit of time visiting it too.

The 62' predator is a great sea boat. Very good running boat in a sea, but it's very nimble if you put it through it's paces in turns. At 30 knots the boat turns like it's on rails and can do very sharp turns. It's a deep V with no tunnels and turns like jets (they turn sharp but tend to slide around too much) and Arnesons (tend to start cavitating the props) can't do....... Put it through some tighter S turns in the ICW at speed and you'd be grinning ear to ear too. If you look at auto racing, there are 3 main types........straight line (drag strip), an oval course (nascar or F1 usually) and road racing with lots of turns and twisties........each can provide a thrilling experience........wringing a bigger relatively fast boat through twisting turns at speed is thrilling.......it's not just all about going straight and fast. And you don't have to be doing 80 mph in a straight line for a thrill....... I prefer running Indian Key Pass or Lostmans river near Everglades City, FL at 50 mph +/- and turning and cutting through all of the mangrove islands than the straight aways where I air the hull out. Not only have I driven many different fast boats, I own one, and have owned several over the years. I also used to drag race in Fun Ford Weekends street renegade class.

If that's your thing, you should try pulling 4+ G's strapped inside 13' jetsprint boat, capable of 0 to 60 in 2 seconds.
Normally, you only can if you have your own boat, as either driver or navigator, but there are folks in NZ who had a custom one built, to accomodate 3 guests plus their professional driver.
THEN you will tell me how thrilling big boats are.

Well, the real beauty is 58 knots and the ability to cruise easily at 45 while a good ride. The 80 also has great visibility from the salon. I think you'll be very impressed with the ride. Also it has 2000 hp MAN's. To me, the AB's are just another sexy boat when looking upon them at the dock, but it's when out on the water enjoying them, you get the exhilaration.

I do think the more factories one sees, the better prepared, but please have someone familiar with boat building factories accompany you or at least familiar with manufacturing in general.

So far I've seen include Westport, Hatteras, Jarrett Bay, Burger, Michael Rybovich (Plus Rybovich yard), Roscioli, Contender, Seavee, Yellowfin, Jupiter, ACY (Now WCY), AB, Heesen, Sanlorenzo, Sunseeker and Riva. All are at least average but all are very different. I know others here have seen far more yards than I have. I've also seen at least briefly a few lesser quality yards in more an investigative role than considering building and been disgusted by what I saw at them. One really diligent trip to some yards would save buyers the heartache of huge mistakes.

I agree with YF, though of course also the general construction must be solid enough to withstand the speeds ABs are designed for, otherwise they would fall apart PDQ.

The fact that these boats take big hits on the used market has nothing to see with their construction quality, though.
Mangustas and big Pershings are not different in this respect, for instance.
It's the nature of the beast, so to speak: only very wealthy people can afford toys like these, and most of them prefer to buy new to get precisely what they want, and they don't mind losing 7 digits amounts upon resale.
So, a low demand with a (relatively) high offer implies that there's only one way prices of used boats can go, and it's down.
At the opposite end of the scale, there are boats like Flemings, which are always in high demand also on the used market, pushing prices up.
Inferring from this market evidence that ABs and Flemings are bad and good boats respectively wouldn't make any sense.
They are both great boats in their own way, but if you are only interested to minimize your financial loss, pretty sure you're better off with the latter rather than the former.

Get a custom Sportfish, it does BOTH.