Yea, alternators seem to last a year or so. It is a easy 20 minute job to swap them. I have one Autozone alternator that I use until it craps out, I sawp to my backup, and get the Autozone unit replaced for free. It is one of the major reasons I put in all gauges, for the volt gauge, and the temperature gauge and the tachometer.
I have not made a car payment in this century, heck not even in this millennium!
I have a "spare" core for a waterpump, starter and one for the air conditioning compressor.