Ah, this works even for expansion downloads? I was under the impression that the trial accounts only included access to the original game.
It's not so much a matter of affording it as knowing that I'd seen it mentioned that it was a lot cheaper. I know people have talked about being able to buy the game for $5-$10, so there's no real reason for him to pay $20+ if that's the case. Plus he's in new zealand, so shipping easily doubles prices on any physical copies.