> It'll be owned by a shell company in the Vigin Islands or some other tax haven & only the ownership of the company will ever change hands so no stamp duty will be due in the UK.

I believe this isn't true any more. Legally, stamp duty will be due at 15% in this case.

Of course, whether this is enforceable, whether the authorities make any effort to enforce this (as opposed to it being a nice sounding law to appease the public), and whether the people involved actually report these transactions are entirely different matters, and I wouldn't be optimistic.