:arghh:
I appreciate the need to keep this on track, but you can't go waving that red rag without expecting a bull to charge in. The legality of choosing which laws you obey or otherwise aside, not all things are equal between the UK and say HK. There is virtually no sales tax in HK, but equally the state services are also limited. Public healthcare in HK is limited to basically emergency only, and even then, there is a charge. Property in HK is stupidly expensive even when compare to London.
If I lived in HK, I would certainly pay less for my camera, but I'd be paying more for my home and healthcare. The system 'works' for them as well as our system 'works' for us.
When you start mixing both systems together, without respecting the 'barriers' (laws) put in place to insulate between them (ie. import VAT, NHS rules), it breaks down. We might save a few bob on a camera, but health tourism costs the UK and hence the tax payer. If we don't want to allow the latter, we also need to not exploit the former too.
Another option, let's harmonise the UK / HK model. VAT receipts account for approx £100bn out of a total tax revenue of £550bn in the UK (2012/3 numbers). The NHS budget for 2013/4 is £95bn. Let's stop paying VAT so we can all get our cameras cheaper and shut down the NHS to pay for it! - admittedly an exaggeration, but it's the thin edge of the wedge.
Whether you agree with the way our money is spent or not at present, it still needs to be funded until such a time as you change policies through the democratic process.