I have been in this spot once or twice in the last 5 years. The cost of the step-up however was not as much as yours.
I was able to get to Platinum each time with a cost that I still think was reasonable.
With this status I was able to use the upgrade instruments in fairly valuable ways (HNL-EWR for two both times) as well as a couple of CPUs. I almost used the 3 bag allowance once but ended up not needing it. The extra RDMs are nice.
A few hundred PQPs and I would say go for it. A couple of thousand PQPs are a bit more than I value Platinum over Gold.