Thanks for all the contributed knowledge and insight everyone! The dealer selling the Studio2 pair told me the same: a defect only ever occurs of you blow something up, and there will be replacement parts available. That's good to know in any case.
I'm still torn over the decision. I need to get financially creative to afford them. The last time I did that was for Donkey Kong 64 as a kid. I finished that game in a weekend before I even started paying my parents back. On the other hand, the Studio2 pair looks like a rare chance. They're in great condition and I don't see any others offered around my part of Europe. I'm in a privileged position and won't get into trouble, so no blocking reason to be 100% financially principled either.
With a bit more patience, a new pair of F228BE could be an option too. I like the low freq specs of the Studio2 and F208 better though. In the end I'll be quite satisfied no matter the choice, coming from 21 year old Mission 74i floorstanders.
I need to build an amp that can handle Revels too. I have a Modulus-86 that can't handle 4 ohm because I messed with the supply voltage. I'll have another one finished soon that can drive 4 ohm to 60 watt but I'm afraid the Revels are more power hungry and I'll lose dynamic range.
Short term I could go for a Hypex Nilai for around 1500 EUR. I'd rather make a real nice version of the Modulus-686. That would be a bit more pricey, and more complexity = more time required for planning and building.