With 3DS XL arriving in just five short days in Europe, UK retailer GAME has launched what seems to be the best trade-in offer so far. If you trade a 3DS console with its original packaging you can get an XL system, and an all-important AC adaptor, for £79.99.
You can check all of the details for yourself on GAME.co.uk, which clarifies that the trade-in console 'must be in original packaging, in good working order and of satisfactory quality'; it's also important to note that import consoles and games aren't eligible for trade-in. Although this page does provide instructions on completing a system transfer from the original model to the XL, there's no assurance that stores will actually facilitate a system transfer on site. One store manager that we've spoken to has said that system transfers will be supported, but it's worth checking with individual branches.
As the release of 3DS XL gets closer we may see some more tit-for-tat promotions between retailers, so it's worth shopping around.