Microsoft scam

My XBox360 is one of those 4Gb storage unit.  Since I don't download much stuff though XBox Live, so I don't see any need to get more memory.  Things go tricky now that I got my Kinect, because it comes with a Redeem Code for a 3.8G game.  That means in order to play this game I have to buy some storage in order to download the game.  Instead of buying yet another Microsoft overpriced hard disk, I used a thumb drive instead.  No way will I pay for another overpriced product.

Also how come this causal game (the Gunstringer) is 3.8Gb huge?  It's like taking forever to download.