Id definitely call it a step up Senator: you would be in HX territory. From what Ive seen, Oscars are excellent value for money and likely to last longer than the Sunbeam. Definitely more suited to milk-based coffee drinkers but as Oscar owners point out, if they need hot water they can use the kettle. Another problem is that they dont have a pressurestat so you cant put them on a timer to pre-heat. I dont know how long they take to warm up.
Do you know how old the machine is or why the owner is selling? You wouldnt want to pay more than a grand ($NZ) I reckon unless it is new or near-new condition. Think about repairs and parts as well. Is there a service agent for NS in Christchurch. A couple of CS sponors sell parts for the Oscar I believe.