Should I just replace the belt tensioner pulley, or the whole assembly?

Should I replace the belt tensioner assembly, or just the pulley?

I am on a budget, and wanting to make sure the whole belt tensioner doesn't have to be replaced, when I replace the alternator and belt?

 

I'm still on the original at 240k miles. Squeals like a mofo until it warms up, so I'm guessing it's okay if you don't care about the noise.

 

I did just the pulley and belt. A month later had to do the tensioner because I couldn’t take the squeaking anymore.

I say replace the whole unit.