6.7 Gb
8 GB
You need 559 Megabytes which is about 0.5 gigabytes
Big butts
it really depends on what you get. If you went to target.com a 4 gb xbox is 199.99 and a 250 gb xbox is 299.99. On ebay it depends on if it is used or new.
About 300 dollars
You said it yourself: 20 Gigabytes.
The main difference is that the Xbox 250 GB holds much more memory than the GB..........and the 250 GB has a glossy cover(i_e the main Xbox's body) while the GB has carbon fiber on it
an xbox 360 with a 60 gb hard drive costs $300 and a xbox 360 with a 120 gb hard drive costs $400
yes you need it
20 gb
GB means giga byte or how much memory an xbox hardrive has