This is the reason that FF miles fetch such high rates in Japan. You could buy (non discounted) miles directly from the airlines and still come out ahead, but discounts (e.g. 1.2 cpm or less) and we also have the Coupon Connection here.

To make a long story short, you're looking at a bit more than 30k miles per ticket (you need to find award seats, though), which are worth no more than 1.5 cpm. Even after you add in taxes, you're still under $600 per person.