First, let me just say that this would be my first Fallout game ever.

I've played Skyrim, but was disappointed with how little your decisions shaped the game world.
After having researched Fallout: NV, it sounds to be far more tightly knit in terms of progression through the game, and I like the idea of losing the ability to join certain factions if you choose to side with an opposing faction.

I'm also interested in Fallout:NV's story, which I have heard is well written, and which will be greatly appreciated by someone whose only other modern RPG played is Skyrim, the story of which is quite lacking.

To sum it up, I'm unable to get myself to pay $30 for a game that I've seen go on sale for $20 or less during Steam sales, and I need you all to say things about how marvelous Fallout:NV is to convince me.