Purchase AAward Miles for Tickets

Hi. Thanks for your help. I was looking at the AAward miles that are on sale now, and if a business class ticket to Asia 2, is 140,000 AAmiles, and you spend, $1,758 for 55k AAmiles, and $2,559 for 85k and the cost of the ticket to Vietnam on JAL was $5k, buying the AAward ticket would give you a great deal?

Does that makes sense?
That is... if you can find a JAL C AAward.

Thank you.