Please help decide..

I am booked on Nov 17 to go EWR - NRT... Current 1K member, and I have requested MUV + Cash upgrade. The availability looks like below:

J9 JN9 C9 D9 Z9 ZN9 P9 PN0 R0 RN0 IN0 I0

For couple days earlier the availability has r6. I have GPU and I can change my tickets and get an instant upgrade.

Question: Change of ticket is $610 + $300 (change fee). So $910 + GPU in exchange for $600 co pay + 30,000 miles

What should I do? Or you guys think I will clear ...