A good example of an Omega is a great car still. But, as others have intermated , finding one without terminal rust is the real issue.
As someone who at 17 in 1970 bought a £30 Austin A40 that had an MOT, but was an absolute rust bucket, but had no mechanical knowledge, I know what you are facing as a youngster. However, with a lovely uncle, who was retiring as the Chief Mechanic for the London section of the GPO with their green Austin vans, i quickly learnt how to keep my rust bucket going mechanically - removing the head, replacing valves and tappets, with a clutch replacement - along with going to night school for car mechanic lessons, I kept it on the road until I had a brand new Company Ford Escort two years later.
Times have changed - my God they’ve changed in terms of the MOT and the cars were built then - and as a youngster the costs have gone through the roof. For instance even as a female very young driver, the insurance cost me just £30 per year. Petrol was also around just 6 shillings per GALLON
But, if I was to be a youngster again I would still buy a cheap, but relatively sound car car, to run for a year or three, whilst also learning car mechanics, then after go for a newer model for a longer period IF you can afford it. Also with driving history building your insurance should gradually reduce.
But after all said and done, as much as I love Omega’s as a mature lady , I would NOT recommend one for anyone under 25, especially if they have no mechanical experience. Instead go for a great modern hatchback, with a 1 to 1.5 litre engine. MUCH cheaper to run, and should not give you the worry and headaches of running a 21+ year old Omega, with even a smaller 2.2 litre engine. I would stick to your Corsa or similar. (My two lads had them before getting bigger cars later)
In addition, if you choose that car wisely, when you come to buy another more modern car, you should be able to trade it in . No sensible dealer will now give any trade in value above what it is worth in scrap :'( :'(
Sorry if I have broken a dream to own an Omega, but you must be realistic in not taking on an “old persons” car!!!
All the best in your decision making