Replacing alternator at 128K. When do you consider buying a new car?

[Sissy]

Maintenance update. 128K. Awful grinding sound from the "engine" area. I got nervous driving home. Towed it to Toyota the next morning. Was New Year's Eve.

Sales rep had me frantic offering me a Corolla for $249/month payment. What did the sales rep know that I didn't about my car????!!!!

Turns out it it's the alternator. I asked, check the starter too, please. Maintenance rep came back with additional cost to change the drive belt. Isn't that included?

Anyway, around $1,400 for an oil change, rotate tires, new drive belt, new alternator (I'll check, but I doubt it's a rebuild.)

Apparently, these parts are not as readily available. The sales rep kept bringing that up. Is that a concern? It is taking 4 days to get the work done. But it was New Year's Eve and I'll get the car back on Jan. 3.

I was hoping to drive it into the ground. (It's getting 36mpg and gas is $2.40/gal.) Opinions? With the alternator/belt done, where do people stand on keeping a car or getting a new vehicle?