Well, it isn't 2012 yet so.... we will see.
There is virtually nowhere that you can find a new Macbook for that price. I would suggest going to eBay and searching for one there, but again, it is EXTREMELY rare to find one at this price.
Macbook Air.
yes
September 2012
First thing you do is save your files to discs. Next, deauthorize you account from your old computer. Then, import your files to your new MacBook. Finally, authorize your account from your new MacBook.
By "new", there could be more MacBook's coming out with higher processors but that's about the only thing that will change about them. If you are worried about buying a MacBook and then a new version coming out shortly after, don't bother worrying - if you need/want one, just buy it. To answer your questions; no. At least not one with any important changes.
no
yes
2012
Neither. Apple has free shipping
A Macbook Pro is the best new Apple laptop. Ram is something that goes inside of the computer to make it run better. But yes, any Macbook would be good for a new user.
No.