Hi Gus, what a beauty - these green PVD Autavias are extra rare, and often for those few that do turn up the PVD coating has not held up so well as yours.
I'll let others chime in about prices or you can look at Rich's excellent table here:

http://www.heuerpriceguide.com/#/autavia-70s-80s/4561057249

- I'd rate the specimen in your hands as good also assuming it may have to undergo a service.
Consider price recommendations in the table are for head only and yours has the bracelet too.
Cheers,
Fabrizio