Is there an easy and cost effective way to curb scratches on aluminum alloy rims?
Off hand, I was thinking about just sanding the defective area with a very fine grit/wet sand...
if the scratches are deep, then you'll be there all day with fine grit paper. aluminum is soft and plugs up tools quickly. Might have more luck with an angle grinder.
Also beware if your wheels have a finish on them then doing this will make it look like crap.
Most people just leave the scratches.
The easiest most cost effective way is to slap a hub cap over it
The basic answer is no. There are ways to fix them, yes; the details are dependent on how deep and extensive the scratches are and how complex the wheel is. But all of the necessary techniques to do the job correctly are very labor intensive (or expensive to pay someone else).
Plenty of videos on YouTube to demonstrate the techniques, but only you can decide if it’s worth the time
