that seems fare enough to me, If I could find a local machine shop that would do it it would certainly be well over that. Though I may try exploring that route as well if they have the tooling to do it or confidence to repair it.Looks like individuals are about $25 with shipping, though shipped from China. Material is probably $15-20 depending on the metal you want it made out of. So my break-even would be about $60 (so that + beer ). If someone has a cutter already, they can probably do it cheaper.
I did validate or check with Grizzly for spare parts, I was happy they at least recognize the machine and i could talk part numbers but unfortunately spares of this part not available and no suitable alternative part.
So its definitely repair or replace.