you could buy an amazon gift card on gyft and then your number of choices grows much larger!
I wouldnt waste it on a gift card.
When gyft 1st came out, and my btc rate was low. I bought a $50 card for .1, now look at it.
If you need to buy something using bitcoin I`d recommend snapcard.
The price is always going to change. That .4
BTC he has now might be worth $400, no matter how he spend it. I spent at least 5
BTC+ on things, and was shocked when the value of those coins rose to $1,000 each. So it doesn't matter what he buys.