Omega Constellation Quartz 1977

I've seen them around for 280-350€ - this condition with a few dings here and there would make me look for another one or at least pay something in the lower end of the spectrum.

The case design is something different, I personally quite like them, to me it's a funny watch for a leisure Sunday. I don't think it's every collector's wet dream, but if you like the style it's definitely an affordable entry-level Omega. Also, if you wear it for a while and end up not really falling in love with it, I doubt that you'll lose a lot of money on it (if any money at all) within a year or so.