Origin is online store that was developed by the EA Sports in an effort to provide one place where fans can obtain PC games from this developer. One of the negative sides of the Origin is that is limited only to the games that were developed by the EA and if you want to buy a game from some other developer you will have to look for it on some other distribution center. However, if you are a fan of the EA games you can be sure that if EA has released certain game in recent period such as Dragon's Age 2 and Star Wars: The Old Republic, you will be able to find it on Origin.
In regards to the prizes, there are no differences between buying a game on Origin or buying it in some video games shop. However, one feature that Origin is offering unlike similar services is the list of friends with whom you can play games online. Once you have downloaded a game from Origin it will install that game on the local hard drive as if you have put a CD with that game. For the fans of EA games, Origin will be a very welcomed service that might improve their gaming experience.