If I do get that GPU now, I might just dispense with running CPU-only tasks from Einstein, as the gravitational wave tasks seem to be taking 3/4 of an hour to complete, and earn 10K credits each!

A good GPU application can produce a huge amount of work.

My very first video card was a Hercules Graphics Card Plus with 64 kB of memory onboard. How far things have come since then!
Of course, it was mounted in a 1st generation 8086 clone running DOS 1.0, cost me $2000 -- no HDD, the driver for them didn't come out until DOS 1.1. What can you get for $680 these days? My first HDD cost that much -- a 20 MB Seagate. And then there was the printer -- a wide-carriage Epson dot matrix for around $1400.
So that's over $4000 -- what can you get for that these days?
I for one do not dream about a return to the "good old days" Kids these days do not have any clue how good they have it.