After an arduous transfer process from AMR, I finally have miles in my AM account. Unfortunately, the round trip first class JFK YVR award ticket for 70k miles is now half gone; I only have the outbound leg.

I can book an economy ticket with miles and upgrade... or should I pay cash for an economy ticket and maybe upgrade? Or should I just sit and wait and hope to get in off the waitlist?

Looking for advice. I'm now on the waitlist for both business and first class on the inbound leg.