You might want to keep an eye out for one of these, a Seamaster 120M Cal 1120 automatic, very strong movement with a chronometer rating and a nice bracelet with clean dial design, very affordable these days as well, possibly one of the best entry points into a modern automatic Omega IMHO, I've seen them at around the 350 quid point in good shape.
This reference is a model 2501.81
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