If I were you, I would not be in a hurry, but would collect a little more, at least 1 BTC. After all, there is no urgency to make a gift right now, so the more you give, the more pleasant your nephew will be. I consider you a very reasonable and generous person.
Do you know many people with several thousand dollars ready to be thrown at something that won't be tapped for many years? I don't. Unless you bought one in the $200 range it's not going to happen.
This is a cool gesture that might be a nice bonus some day and that's how it should be treated by the person providing it too. No point in wiping themselves out.