If you fly to somewhere in the EU and back then you have no problem. You only get charged import Duty when you buy something from outside the EU.
You can buy VAT free stuff at Dixons Eurotunnel too, which saves you dragging anything you buy onto a plane (which some airlines actually charge you extra for).
But surely if you buy something in a UK airport and collect it when you come back (assuming thats possible) you dont need to pay any VAT or import duty? After all you arent importing anything, and there would be no point in having a VAT free shop if you had to pay VAT on everything once you leave the airport.
And if you did take the camera to a country outside the EU and brought it back to the UK then you havent imported anything because you bought it in the UK. You might get checked at US (or wherever) customs but you can just show them your bought it in the UK and are taking it back there on your return flight.
Unless, I'm completely missing the point there really is no problem.
When you buy a product here at a duty free shop you are buying it to export to another country, hence no vat/duty is paid on that item, and you should be buying it cheaper than you can buy it in the shops here (but that's another story). When you arrive in another country, if you are a permanent resident you should abide by their import tax rules and declare it, and pay import taxes as required.
If you are a UK tourist - as we're talking about here - then when you return to this country then you are legally obliged to pay import taxes - vat and duty - just like any commercial importer brings the goods in to this country in the first place. But..... you have a personal tax free limit - £340 - and the usual limits on alcohol, tobacco etc, which does not concern us here.
So if you buy your camera at the airport tax free, or overseas, and it costs less than £340 then when you return here there is no need to declare it and you walk through the green channel, or blue if returning from an EU country. The coloured band, blue or green, on the luggage tag identifies the fact that you are returning from within or outside the EU.
If you buy a camera costing more than £340, either at the airport here or overseas from a non-EU country, on your return - in theory - you should be walking through the red channel and declaring it. You pay vat (no duty on digital cameras) on the full value of the camera - not just that above £340.
If you have bought from within the EU, then taxes have been paid in the purchasing country and you are free to walk through the blue channel with any value.
If you try to purchase an item at an airport at a tax/duty free price and you are destined to travel within the EU then in theory you should be prevented from paying the tax free price at checkout - they check your boarding pass. However, some airports here (Heathrow and Gatwick are the only ones I travel from) announce "tax-free prices for all travellers". What they are really doing is reducing their inflated prices down to a level you would be able to buy for here anyway. Not a High street price but an internet price.
The scheme whereby you buy tax free at an airport here and they post it back to your home is a relatively recent innovation, and I can't yet say with authority what HMRC's position is on this, and I am currently waiting for an answer from them. I'm sure it's not a problem for items below £340, but for above this I would say it could be.
However, Some 3 years ago, before the recent £340 limit was introduced, up from £145, I bought a Tom Tom from Dixons at Heathrow for £360 and had it posted home without a problem. And herein lies the moral, when I say check your prices carefully before buying at an airport. I thought I had my finger on the pulse as far as Tom Tom prices were concerned, and had a figure of £400 internet price. When I returned from my trip nearly 2 weeks later I found the internet price was £320. Since then, I have yet to find anything significantly cheaper at an airport, if at all, than from an internet supplier.
But surely if you buy something in a UK airport and collect it when you come back (assuming thats possible) you dont need to pay any VAT or import duty? After all you arent importing anything, and there would be no point in having a VAT free shop if you had to pay VAT on everything once you leave the airport.
This little bit where you say you aren't importing anything is the part where many don't understand ports of entry. Taking an airport as an example. They are physically divided in to landside and airside. When you go out through the immigration desks you are crossing that divide and moving from landside to airside. There are restrictions in place on who can cross that divide. For passengers - a valid boarding pass (and passport as necessary). For airport workers, an identification pass with the authority on it to go airside. The duty free shops are airside, and as such have goods within which, legally speaking, have not yet been imported in to this country. When you buy and return, by passing through immigration and customs, from airside to landside, you are then importing them. It is at this point where import tax/duty is levied.
The cargo warehouses have similar divides. Airside areas containing goods awaiting payment of tax/duty, and areas landside where payment has been made and awaiting collection.
Purchase made over the internet and received by post have different values and processes.
I hope this clarifies some points for you. If not........chocolate make me feel better.