The only caveat I would add to the above is that suggesting not buying a Japanese keyboard model if you're a software developer. The layout is incredibly different, and you will be scratching your head trying to figure out where certain symbols are or why the layout is slightly different (specifically w.r.t to parentheses, braces, and whatnot).

Another thing to note is that Apple changes its prices very rarely, presumably because their corporate treasury department has very large contracts for dollars, so they don't have to worry as often about fluctuations in currency -- but that said these deals don't last forever.

Lastly, Apple products' warranty is good worldwide, so unlike most products you buy in Japan, you can be rest assured that Apple will honor the warranty wherever you end up, and taking it into the store is no problem at all.