I just purchased a Romaine Gauthier which is in the same limited bracket as Grönefeld, It was about 1.5 years old so still had factory warranty left and in mint condition, I also know the provenance. I experienced the same hesitation as you but by looking for a used one from a very reputable dealer I paid much less than retail. I don’t know what the watch is really worth because there are only 4 others I could find but my price was in the same ballpark so I felt good about the process. I love the watch and am not worried about the market, with independents that are very limited you have no guarentees but as a rule of thumb can count on most of the models losing some value. When you buy a really good used one you take the hit of initial depreciation away and hedge your bet. Hope this helps...Jim