Omega 2506-7

hi all,

as shown in the 30mm-thread, I´m a bit fascinated by this kind of watch.
In germany usually one have to pay 250-350 euros for a good example of 2639 or 2791, 2750, 2504 etc...

This 2506:

http://www.ebay.de/itm/131523099904?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

is bigger (=more expensive) and i´m not sure, what i shall offer to the seller. He wants 500, I offered 450 (euros).
so it would be nice to read some opinions about that watch and it´s price.

rgds - h.u.