Alternator Pulley Inconsistent Spin (is this a sure sign of a bad alternator?)

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So the alternator belt on my kia rio broke I made a post and got some good responses about what to do and decided I would replace all 3 drive belts (good thing too as the AC belt looked SUPER worn on bottom). Anyways as I’m doing this I decided to check the alternator pulley (I had done so previously and thought it was fine) and actually noticed that it didn’t spin as smoothly as I originally thought. It’ll spin easy for maybe a 1/2 to 2 rotations and then it’ll have some resistance and repeat. I do think the belt was super old and worn and that was the main reason for it breaking but this could also be a contributing factor and I already suspected the alternator (really i suspected a weak battery until recently tbh) I was having issues as I frequently had to jump start my car and when the belt broke it wouldn’t start back up. I’m checking on here to for sure know if I should replace it or not I called and checked and it would be about $200. Just wanting a second opinion before I commit.