Achievement points are just for bragging rights. They cannot be used to buy anything.
Yes you may.
No. You buy the points so you can buy things on Xbox. (Microsoft points)
You can buy items on the Xbox Dashboard Marketplace like map packs, trailers, other downloads and games. Also you can buy stuff for your avatar.
Get a job or get your parents to buy it for you....
you can't use points to buy xbox live membership. You have to buy them both seperately.
No. You earn gamer points playing games, Microsoft points are to buy things on the xbox live market place.
you buy a card at a store for xbox live and enter a code. That code gives you points. With those points you can purchase downloads
Xbox live points (Microsoft points) are used to buy things in the Xbox live marketplace. Such as game add-ons!
you have to buy them
Yes you can buy it with a credit card.
Either register a credit card and buy points with that, or go to a local video game store and buy a points card and scratch off the code, then go onto xbox live and select redeem points and put the code into the xbox.
An Xbox 360, and enough points to buy it on the store.