I wouldn't describe them all as 'mint condition', photos tend to hide a lot of blemishes.
I do try to avoid purchasing 'rust' (with the exception of Dutch lugers
), though. Prices in Europe, particularly because of the stricter gun laws, are usually much lower, which also helps one to sift through the offerings a little better. Also, it is possible to take advantage of the differences in local gun laws, which also affects prices. Guns that are virtually unsaleable in one country, can be owned in another, provided the paper work is in order. This means you can buy them at an interesting price in country #1, then export them to country #2.
I broke my own 'law' once, and I keep that little gun as a reminder: condition, condition, condition.
A good place to start is the German auction site 'Egun'. Another interesting auction house is 'Hermann Historica' in Munich.
And, of course, if you look for something specific, contact the European collectors directly.