There seem to be differences between countries as well, with Germany being more expensive than, for example, The Netherlands. I would expect to be able to buy a car such as you describe for no more than 30,000 euros, provided it's from a private seller. For the same price at a professional trader, you would get a car in substantially less condition. The 280 SL has always been quoted as somewhat more valuable. Large discount for not having the softtop. A 5-speed is much sought-after, although I am not sure it is worth the extra price you would need to pay.
Prices in the US are still lower than here in Europe, as they have been for most of the past decade and probably longer. If you are looking to import to Korea, it may be more economical to get a good car from the US.
What always strikes me is the number of cars continuously for sale. Here in The Netherlands there are easily 100 available immediately at any given time. This probably holds true for most other classic car makes & models. This should depress prices.
What I always recommend is to buy a car that is (near, not exactly) perfect for no more than $45,000, because in order to get a car to near-perfect condition will have cost someone around $90-100,000 while the top-price that can be had is usually no more than $45-50,000. Investing $90,000 only makes sense if you intend to keep the car for a long time, because in that case you will get the returns in the form of much lower upkeep through the years.
If you pay much less, with a view to holding onto the car for many years, you will encounter expenses that will tally up to quite a bit, UNLESS you can do most of the work yourself, like I try to do (which to me was one of the main reasons to buy this car in the first place!).
Also it pays to shop around for work you cannot do yourself: two years ago I was quoted a price of $9,000 for a paintjob and some welding etc., and I ended up paying $900 at a less-reputable shop, while the quality came out at 90% of the more expensive place. Today, people are always commenting on how beautiful the car looks and a lot of that can be credited to the $900 paint job.
Cees Klumper in Amsterdam
'69 white 280 SL automatic