It's more so we can discuss what we see happening in the market - like this thread over for 355s -
F355 Market
Simply put, the Gen-1 R8 is going to head up in value - something I've been saying for years on this forum. I think we're starting to see some of that occurring now, and the manuals will lead the way - but it won't be limited to the manuals.
The R8 was a critically important car for Audi - their first production supercar. It just so happens that it's also a winning formula that people desire: (a) beautiful and timeless design, (b) high-revving naturally aspirated large engines (V8 and V10), (c) manual gearbox option, (d) analog experience including hydraulic steering, e-brake, etc. Now, add in the racing lineage - the R8 carries the namesake of the Le Mans car that made history, dominating year after year, including taking all three top spots during its debut. The GT car went on to have similar successes, giving the R8 a truly desirable motorsport heritage that even most supercars don't have.
Jay Leno has said before that one of his measures for a car's future collectability comes from looking at how it was received when launched. Now, this isn't always a perfect indicator as some undesirable cars go on to be desirable down the road, but it's rarely the other way around. The R8? The entire first year of production sold out in a week. Pretty darn desirable. Add the pop culture (e.g., Iron Man, toys, video games, posters, etc.) and it only amplified the appeal of the R8 beyond the car enthusiast to main street.
The Gen-1 NSX, which has a small fraction of the aforementioned going for it, and also included a much larger sales volume here in the US (~9K NSX vs. ~6.5k R8) has seen prices rise to above original MSRP in recent years for quality examples.
The R8 is an icon... for all of the reasons mentioned here and so many more. Being a VW / Audi product, it also means there's no shortage of fans in the ecosystem who have grown up drooling over it and had it on their bucket list. The car's own credentials, and the built-in demand of generations now coming into some disposable cash, can certainly put some upward pressure on prices. And needless to say... if all of this wasn't enough, and you're simply a car enthusiast looking for a great looking supercar, good reliability, a large cylinder-count, high-revving engine mounted in the middle... you're just not getting that in any new car, so cars like the R8 will be your go-to option.
For me, it's all a bit inconsequential. I bought my R8 new - spec'd it exactly as I wanted it, and my intention is to keep it indefinitely. I wouldn't sell it for $250k or even $300k. It just simply couldn't replace the joy of the R8 for me. Nonetheless, I do hope they rise in value as it's a car that deserves the recognition for what it is - a fantastic modern classic.