So all I can do is imagine it's gold plate. Looks legit but entry level or presentation level. Maybe $250 US...
Oh darn, @ahsposo beat me to it Fredenz if you are enganging in buying an old Omega you might want to do some research. Have a look at some of the stickies in the vintage section.
Also, this is a nicer way to ask (see the posting-guide link above): https://omegaforums.net/threads/first-time-buyer-without-a-clue.64988/ . If guys are going to help you, most would like a little more info. Introduce yourself etc. explain why you ask. Stuff like that. Makes people more inclined to help
Fredenz, the inside of the caseback is the part of the watch where its reference is indicated. If you post a picture, it will be much easier for us to provide some info as to the value of the watch.
Looks like this one with a different dial: But the reference number should be engraved inside the case back. Hope this helps, gatorcpa