Not planning to buy one mind you but wanted to get the opinion of the vintage zenith enthusiasts here.
Well, vintage is easy - if you're going to get just one, you have to get a Primero. References range from around $2000 to $7000, so that 'll leave you anywhere from $3000 to $8000 to play with. I'd suggest an A 385 for the characteristic trapezoidal case and a graded-fume dial that gets better and better the more you wear it. It's completely underappreciated, so you can get a nice one for under $3K. The new purchase is actually the more interesting. I see the options as follows 1. Zenith Striking 10th - this is the watch that relaunched the manufacture after the years of excess and eccentricity under Thierry Nataf. 2. Zenith 36000 VPH - this is the modern Primero chronograph (new one's on the left) 3. Zenith Winsor annual calendar - Primero + annual calendar You'll probably have to shop a bit to get a good price to make it under your budget, but it is very doable. For example, Striking 10ths are starting to hit the secondary market in the $6K range. 36000VPH are still less. Gratuitous shot of Thierry Nataf at one of his bizarro product release bashes in Dubai:
A strong argument can be made that the winsor in steel is the best bargain among the modern watches today. While I love the striking 10th, if I were to buy a modern day zenith, I would probably have to go with the winsor.
I really, really want one of those A386s, I couldn't justify going too deep into Zenith but having that one piece would be an awesome way to capture the essence of the brand. Feel free to point out any excellent examples of them Zenith crew!