Do NOT get your nephew NBA Live 2007. That game is a glitch-filled castostrophe (just check out all the b!tching , rants, and petitions at the NBA Live forums). If you want to get him a great basketball game, NBA 2K7 is the game. Otherwise, Madden 2007 would make a great gift too.
Check Amazon.com for deals on NBA 2K7 & Madden 07; they tend to sell them for $5-$20 cheaper. I got the 360 version of NBA 2K7 for $40; which retails for $60.
Yeah, the Live series is crap, and 07 just may be the worst yet. Madden 07, for the 360 at least, is pretty good. I don't even really like football, and I enjoy it. NCAA 07 is better in a lot of ways IMO though.