I don't think I saw Nintendo's
voucher program mentioned on here at all.
TL;DR - if you are willing to switch regions to Sweden or Australia, you can get two Nintendo-published digital games for £37 each (mostly £49.99, some £59.99, usually) and enough Gold Coins to get something like BOXBOY/Picross S3 for less than £1. Combined with the "game sharing" you can do with digital games, this works out great.
Seriously, the sharing feature is saving me and my sister a ton of money for games that we would both otherwise buy separately.