New transmission

Is it worth putting a $1400 transmission in a 2002 Suzuki station wagon with 140,000 miles?

Samurai or wagon? Samurai was a tiny SUV, never a wagon. You tell us if it is worth it, how is the rest of the car?

In accounting a repair like this adds on to the life of the machinery, and isn’t treated like an expense. These are called “extraordinary repairs.”

It’s either 1.4k for a new trans or 10 - 20k for a new car.

Probably only if you’re planning on driving it for a long while longer. This is a pretty quickly depreciating vehicle and so in terms of resale value, recoving the cost of the repair is probably a toss up. But it’s also a perfectly nice car with a known history, so if it’s in otherwise good condition and you want to keep it, go for it.