The Defender/Disco argument is apples to oranges. A 5k RoW Defender is going to be a hell of a lot more likely to have any rust issues in the frame than any 5k D1 or D2
Who is having that argument? This is a Disco/Disco argument. It's granny smith gasoline V8 apples to red delicious 200tdi diesel apples. A $2k 200tdi Disco from Europe or the UK that you actually inspect and ensure isn't rusted out horrendously plus $3k to get it back will be better than every other clapped out Disco somebody is selling for $5k.