Markos,
I understand your approach, and it is one I'd prefer. I did travel a few hundred miles to purchase the '74 e9 4.5 years ago.
However, I've purchased 8 'pre-owned' cars over the past 15 years via the internet without laying eyes on them directly. In each case I have communicated extensively with the owner, or someone responsible for listing the car. Some were from dealers, and some from private sellers. We usually had about a dozen or so emails and additional pictures sent, along with as much 'history' of the car as was available. I went through this with the 3.0 CS before I drove to RI to inspect it as well. One purchase was from a man I 'kind of ' knew from following his posts on a forum similar to this one for about 3 years, thus I was very aware of his outstanding character. I didn't negotiate price on any of them, just asked the seller for the lowest acceptable price, telling them I'd either say 'yes', or 'no' to that figure. Either way the interactions regarding buy/sell would end.
In all cases, I've found the cars I bought to be every bit as good, and maybe superior to what had been described and what I'd expected.
Just my experience, others may vary!!
Gary
PS: I'm not a flipper. I owned each of these cars for at least 4-5 years (one for 10) before I 'itched' for a different ride, then scratched that itch!