Wife hears noise once and a while, dealer assessed at the recent 60K service that the front right outer CV was failing.
How close to the 60K service was it? Your factory powertrain warranty covers this part for 5 years or 60000 miles.
If under the 60000 you have warranty. If just a little bit over, the dealer may be willing to have it taken care of as a customer good will repair if you have had services done there in the past. You may even want to check with Subaru for any good will assistance.
This is what I would be doing.
Aftermarket axle on a 2017 with 60k, lol. If a CV went on a car I bought new at 60k I wouldn't be paying for it. The dealer is trying to soak you, OP.
Really? Around here even if you are a bit within warranty mileage they deny

But they are overcharging on labour, but Subaru shop manual wants tech to unbolt the strut from the hub assy and the redo the FEA, The shad tree "cheat" is to separate the lower ball joint so no alignment is required then the job is only 1/2 hour after the car is in the air and the tire is off.
They soaked my wife for $228 to just bleed the brakes!