Depreciation is a way bigger factor than any remedial work costs.
My X5 is worth nowt (well say £10k), but despite 85,000 on the clock it looks like new is serviced for £100 a time at the village garage, has had one £600 bill in the last 5 years, costs £200 fully comp.
It's new equal would be £55k with the same spec. so that for sure will be run until my youngest finishes Uni (she's still at school) and I no longer need a hauler.
I see no reason the Zed would behave any different on a pure cost model