The biggest issue that causes the early demise of these motors is not getting the timing belt changed in a timely fashion (every 60k miles), which leads to them snapping, and bending valves, etc. Keep up with that, and regular maintenance, and they're not THAT bad of a motor. Digitaloutsider (I think he'* on here, too) has nothing more than 96+ intakes, EGR delete, gutted cat, WOT-Tech chip, and WAI on his Cutlass Supreme, and he ran a 14.8 @ 95.0 (granted his is a manual).
That'* enough to put some (I said SOME) L67 equipped GTPs to shame.
The 3.4 Euros are indeed rare. I've always loved the key-colored taillight trim on those. A CD player in a gen I Lumina is almost rarer, especially a FUNCTIONING one. That sunroof is aftermarket, though (not an option on Luminas). The before and after pictures remind me of my TGP'* clean up.
All in all, I'd say definitely a very good buy.