I do wonder, when 350bhp.is hot hatch territory today if some cars are a case of 'dont meet your heroes'.
I understand a massive chunk of value is tied up in nostalgia and image but I do wonder if it would be 'worth it'. I struggle with quite a lot of classic car pricing today. When a Ford Sierra (and not even the really quick ones) will set you back more than an Aston, I feel like I've missed something somewhere. 
I think what made the LC special is, even today, it's not short on power, and there were no real compromises, its a big, comfy semi-exec saloon. You can hold a conversation in one at 140 (so I've heard, obviously) easier than many cars doing 40 without having to raise you voice. And its 35 years old. Thats how ahead of it's time it was.
At the time, the Granada was a crock with that old 2.8, though shortly followed by the better 2.9, Rover was doing the 800 Vitesse, and that was about it for European big execs.
Obviously, from a technology and gadget perspective, if thats your thing, its badly dated - mobile phones weren't really a thing for most people, let alone smartphone control of the car. Looks wise from the exterior it looks like, well, a 1990s Vauxhall.
I wouldn't own one now, because I would not be able to keep it in the condition it needs to be kept in, and few remaining need to be kept tip top for the future.
A true icon.
......or torque.
419 lb ft of twist is impressive even in 2025. 
This ^^^^^
People seem obsessed with BHP these days, but on most cars max BHP is usually about 4500-5000 RPM, and that's not a region you can drive comfortably in. Torque is a better measure of the driveability and acceleration available, and a nice flat torque curve from tickover to red line is much preferable to a peaky torque curve which is typical on highly tuned "max BHP" engines.
The LC is a big heavy old bus, but if your clutch will take it can supposedly do 0-60 in 5.2 seconds. That was excellent in 1990, but is perhaps less amazing today. However, IIRC 60-120 was also something like 6 seconds, and that's were the torque of the big old bus still excels. It doesn't really run out of grunt till north of 160.
I've never checked if it is actually true, but there was a tale that the LC produced more torque at tickover (or 1500 RPM?) than the 3.0L 24V engine in the GSi Carlton did at full chat. Might be bolleux though.