Ironically, I was thinking seriously about having the shop do the work when I had a self-inflicted incident while driving my wife's car that we bought in 2015.

The repair estimates were within $50 of each other. Hmmmm... spend the $1500 repairing my wife's newer car, or spend it on my 150K-mile 2002. Only enough $ to fix one... and doesn't my wife's car look nice!

So, it really does come down to a) I do something myself, or b) it doesn't get done at all. I appreciate the replies and will do further research to see what I'm willing to take on myself.

EDIT: FYI, the estimate for repairing the WRX did NOT include repairing the rusted area by replacing the metal. They told me they would use some hi-zoot... epoxy? ... and, BTW, no warranty on rust repairs.