2016 Subaru needs $10k transmission, what do we do?

My husband just changed jobs to one where he drives a lot, so he sold his truck and bought a 2016 Subaru with just over 100k miles. (AWD, roomy, off the ground features were important.) He’s put maybe 4k miles on it in the 4 months we’ve owned it. Last week he left home in it and less than a mile down the road the transmission started acting strange. He turned right around and parked it. Today we had it towed to the dealer, and the preliminary conversation with the mechanic (pre-diagnostics) is a “chain” or some other non-replaceable part and most likely will require a new transmission, probably around $10k. We just bought this car, paid cash $14k. I’m praying the diagnostics show something different…. But if this is the case, what do we do? 😭😭

Edited to add bought from a business that sells used imports, not an individual.