INA or aftermarket serpentine pulleys?
 

The idler roller of the accessory belt drive on my car is rolling roughly and noisily.

I presume the original rollers are from INA. Well, on my German car, I already replaced three belt pulleys, and I think it's likely to just get crappy again before 100k miles. But I could only find the INA roller in one place and it's $50!!

Are any of the aftermarket ones known to be any good? They all cost less. I'd like to know if you bought one of the aftermarket ones and noticed if it came with a good bearing or chinese, and whether you think the plastic roller is sturdy enough for the job.

Depends what brands. Japanese parts are high quality too. For example GMB is made in Japan. I actually like them better than INA (Made in Slovakia).

Yea I noticed the timing belt rollers I took off were marked Germany and the replacements marked Slovakia. I ended up finding a slightly lower price on the INA part (the roller itself is marked FAG, same company different brand.)

I am not sure about GMB, the last GMB I received was made in china and I did not like that and resold the part.

I saw the parts store roller numbered 5035 or 45035. It's about $25, but I couldn't examine it without paying for it first.