These big-bore No.1's exert a strange fascination. I've shot one, and I flirted with one on offer for quite a while years back, ended up resisting successfully. They really don't have much utility beyond shooting for fun; few people go to Africa to face an elephant holding a single-shot rifle with occasional extraction/ejection issues.
And as said before, the scope on this one is a bad match for the caliber. Not just the economy quality but also the high magnification.
So what matters to your friend wanting to sell this is that nobody who knows their stuff will pay extra for the scope. He may do better offering the rifle clean and selling the scope separately for a few bucks.