I saw San Jose and assumed California
Those sound like the old prices in the States, before MBUSA started selling G500s for $73k.
I would maybe pick Gilly's brain a little on the V6. I don't think it has any issues and it does have just a little more power than the M104.
50k miles on a '98 is pretty average here, about 12k per year. G's here tend to get driven less, at least they did until this latest round of mass marketing by MBUSA. I don't think the miles are much of an issue anyway. Run synthetic oils and the engine should be solid for triple the miles it has at least. The rest of the drivetrain is super durable. Even the twenty year old trucks remain very reliable. I know of one 1980 280GE with 250k on it. It had a cosmetic refresh and engine rebuild but for the most part it is very original and solid.
Good Luck
