You are on to a great boat with very high owner satisfaction and that's why there are not many that come on to the market.
I have a Toyota Epic E-22 (direct drive). As far as holding its value, my local dealership calls me every other year or so to buy it as they have customers who call them looking for one. Every time I get this call, I'm surprised on one hand, but on another it makes sense. There are plenty of people who are strongly loyal to Toyota/Lexus. When they find out Toyota made high quality inboards, the alarm goes off and I get a call. On a couple of these occasions, I could have sold the boat for a profit. But, it's not for sale. We love it. It's a great boat.
The Lexus V8 will run forever with basic maintenance and 500 hours is nothing if it has been maintained. It's the same engine as found in the Lexus LS. If the current owner has not changed the timing belt, deduct $1,000 from their price and have it done when you buy it. (I had mine changed for just over $400 a couple of years ago.) Also, have a compression test done on the engine before you buy it. These engines are in a lot of cars, so mechanics are quite familiar with it.
By the way, the Lexus V8 uses about 30% less gas than the typical inboard engine. That's like paying for about 2 days of riding and getting the third day for free in terms of gas - pretty sweet.
The fit and finish are a decade ahead of its time. It took most of the other high-end mfr.'s until about 2010 to catch up with the Toyota. My boat is 15 years old and most people think it is 1-2 years old.
To learn more, visit
www.epicmarine.com. If you have the HIN, you can plug it in to that site and it will tell you which options are on the boat and what the original MSRP was. Also, you can see what other S-22's have been selling for in the years since manufacture.
As far as hull and wake shape, the only way for you to know is to test it (this holds true with Toyota or any other mfr.). I wouldn't make my decision based upon people's opinions who have never ridden behind an S-22 or an SX-22. I can't offer an opinion on the S-22 V-Drive because mine's a E-22 D-Drive which has a totally different wake and hull.
If I had to do it again, I'd buy another Toyota Epic as quick as I could get my hands on one that's been well maintained. Great boat. Nuff said.