There are many great Omega starter watches out there for those just beginning and/or with a limited budget. By limited I think these days +/-€400 is about as low as you can go to get something in fine condition that is really worth wearing.
I picked these two up in the last 6 months, both came in around €375 each and both have enough about them to hold their own in more esteemed vintage company.
A manual wind Seamaster Cosmic, which at 35 mm and with this black crosshair dial has quite a nice wrist presence and IMHO ticks all the right boxes with a sunburst finish steel case, tritium markers and contrasting white hands.
And this simple Seamaster Quartz which I couldn't resist at just over €350 due to the nice matt grey dial and sharpness of the 35mm case and bracelet. A great fun watch which is always ready to go.