It depends on different factors.
Which serial no? earlier ones go from 1250,- EUR to 1450,- EUR - later ones even up to 1800,- EUR (all standard 0.72 finder and no specials).
I paid around 1400 EUR for a 0.85 black chrome in mint condition. It still has the old DX reader (golden contacts) and might have not the latest MP finder upgrade (not sure about that).
I would not give any cent more for a "a la carte" model label in the advertisement. It can mean from simply having a 0.85 finder (like mine) without any other "extras" (basically just differentsies, not upgrades) to a optically fully changed model with different levers, leather, finder magnification, engraving, etc.
In my book, they are not worth more money, just different from the usual breed.
You get a good shooter M7 from 1250,- EUR on these days. the difference buys already a lens.
Btw - 1.700,- EUR is around the border, to get a nice used MP (just to cook up some thinking).