If it was in great condition and a 25 inch frame I would have the $250 in hand before the seller changed their mind.
I don't think I would even consider offering less - just pay them and take it home.

I have a '77 LeTour 12.2 in Scarlet. Although not one of my most expensive bikes, it may be my favorite. I'm old and a little over weight, and still average above 17 mph on the Dayton Ohio bike trails with the bike. Can't say enough about them.

I did upgrade the wheels to very nice wheel set using sealed hubs (period correct) with Mavic Open Pro rims. (I have the originals.) It is amazing when you put a great wheel set on a great steel frame, the ride is sweet.