Declaring as a gift means nothing in the UK, you will be charged if the value of the item is more than £15. For handheld consoles into the UK the duty is 0% but the VAT is 20%, and then you have to pay £8.30 handling fee too. So if you write a value of $60 on the front then we will have to pay another ~£16.30 to receive the item.
I understand that you'd be breaking the law to ship from USA with a value of less than £15, but what about shipping them direct from China where they seem to do this kind of thing routinely? It would save a lot of people a hell of a lot of money.
This is the latest info I could find regarding import costs for handheld consoles from China.