Personally I wouldn't pay anywhere near 700 Euro for it!
Neither, its more 150-200 tops from my perspective as its just an old man's watch. Its dated looking, not classically styled like the 50s/60s models or funky like the 70s.
got it for 500 with the box and papers date date back to the moment of purchase. the back of the case is 9 gram 18k gold. (worth about 250e)
its a cal 712 // ref 1530040 //259
I would value it a $1000.+ depending on condition. It is a dress watch and the 712 is an excellent and desirable caliber. It is a watch we call, a Dennis watch.